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pkimpel.retro-b5500/emulator/B5500Processor.js
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/***********************************************************************
* retro-b5500/emulator B5500Processor.js
************************************************************************
* Copyright (c) 2012, Nigel Williams and Paul Kimpel.
* Licensed under the MIT License, see
* http://www.opensource.org/licenses/mit-license.php
************************************************************************
* B5500 Processor (CPU) module.
*
* Instance variables in all caps generally refer to register or flip-flop (FF)
* entities in the processor hardware. See the Burroughs B5500 Reference Manual
* (1021326, May 1967) and B5281 Processor Training Manual (B5281.55, August 1966)
* for details:
* http://bitsavers.org/pdf/burroughs/B5000_5500_5700/1021326_B5500_RefMan_May67.pdf
* http://bitsavers.org/pdf/burroughs/B5000_5500_5700/B5281.55_ProcessorTrainingManual_Aug66.pdf
*
* B5500 word format: 48 bits plus (hidden) parity.
* Bit 0 is high-order, bit 47 is low-order, big-endian character ordering.
* [0:1] Flag bit (1=control word or descriptor)
* [1:1] Mantissa sign bit (1=negative)
* [2:1] Exponent sign bit (1=negative)
* [3:6] Exponent (power of 8, signed-magnitude)
* [9:39] Mantissa (signed-magnitude, scaling point after bit 47)
*
************************************************************************
* 2012-06-03 P.Kimpel
* Original version, from thin air.
***********************************************************************/
"use strict";
/**************************************/
function B5500Processor(procID, cc) {
/* Constructor for the Processor module object */
this.processorID = procID; // Processor ID ("A" or "B")
this.cc = cc; // Reference back to Central Control module
this.scheduler = null; // Reference to current setTimeout id
this.accessor = { // Memory access control block
requestorID: procID, // Memory requestor ID
addr: 0, // Memory address
word: 0, // 48-bit data word
MAIL: 0, // Truthy if attempt to access @000-@777 in normal state
MPED: 0, // Truthy if memory parity error
MAED: 0 // Truthy if memory address/inhibit error
};
this.schedule.that = this; // Establish context for when called from setTimeout()
this.clear(); // Create and initialize the processor state
}
/**************************************/
B5500Processor.timeSlice = 5000; // Standard run() timeslice, about 5ms (we hope)
B5500Processor.memCycles = 6; // assume 6 us memory cycle time (the other option was 4 usec)
B5500Processor.collation = [ // index by BIC to get collation value
53, 54, 55, 56, 57, 58, 59, 60, // @00: 0 1 2 3 4 5 6 7
61, 62, 19, 20, 63, 21, 22, 23, // @10: 8 9 # @ ? : > }
24, 25, 26, 27, 28, 29, 30, 31, // @20: + A B C D E F G
32, 33, 1, 2, 6, 3, 4, 5, // @30: H I . [ & ( < ~
34, 35, 36, 37, 38, 39, 40, 41, // @40: | J K L M N O P
42, 43, 7, 8, 12, 9, 10, 11, // @50: Q R $ * - ) ; {
0, 13, 45, 46, 47, 48, 49, 50, // @60: _ / S T U V W X (_ = blank)
51, 52, 14, 15, 44, 16, 17, 18]; // @70: Y Z , % ! = ] "
/**************************************/
B5500Processor.prototype.clear = function() {
/* Initializes (and if necessary, creates) the processor state */
this.A = 0; // Top-of-stack register A
this.AROF = 0; // A Register Occupied FF
this.B = 0; // Top-of-stack register B
this.BROF = 0; // B Register Occupied FF
this.C = 0; // Current program instruction word address
this.CCCF = 0; // Clock-count control FF (maintenance only)
this.CWMF = 0; // Character/word mode FF (1=CM)
this.E = 0; // Memory access control register
this.EIHF = 0; // E-register Inhibit Address FF
this.F = 0; // Top MSCW/RCW stack address
this.G = 0; // Character index register for A
this.H = 0; // Bit index register for G (in A)
this.HLTF = 0; // Processor halt FF
this.I = 0; // Processor interrupt register
this.K = 0; // Character index register for B
this.L = 0; // Instruction syllable index in P
this.M = 0; // Memory address register (SI.w in CM)
this.MRAF = 0; // Memory read access FF
this.MROF = 0; // Memory read obtained FF
this.MSFF = 0; // Mark-stack FF (word mode: MSCW is pending RCW, physically also TFFF & Q12F)
this.MWOF = 0; // Memory write obtained FF
this.N = 0; // Octal shift counter for B
this.NCSF = 0; // Normal/control state FF (1=normal)
this.P = 0; // Current program instruction word register
this.PROF = 0; // P contents valid
this.Q = 0; // Misc. FFs (bits 1-9 only: Q07F=hardware-induced interrupt, Q09F=enable parallel adder for R-relative addressing)
this.R = 0; // High-order 9 bits of PRT base address (TALLY in char mode)
this.S = 0; // Top-of-stack memory address (DI.w in CM)
this.SALF = 0; // Program/subroutine state FF (1=subroutine)
this.T = 0; // Current program syllable register
this.TM = 0; // Temporary maintenance storage register
this.TROF = 0; // T contents valid
this.V = 0; // Bit index register for K (in B)
this.VARF = 0; // Variant-mode FF (enables full PRT indexing)
this.X = 0; // Mantissa extension for B (loop control in CM)
this.Y = 0; // Serial character register for A
this.Z = 0; // Serial character register for B
this.cycleCount = 0; // Current cycle count for this.run()
this.cycleLimit = 0; // Cycle limit for this.run()
this.totalCycles = 0; // Total cycles executed on this processor
this.procTime = 0; // Total processor running time, based on cycles executed
this.procSlack = 0; // Total processor throttling delay, milliseconds
this.busy = 0; // Processor is running, not idle or halted
};
/**************************************/
B5500Processor.prototype.access = function(eValue) {
/* Access memory based on the E register. If the processor is in normal
state, it cannot access the first 512 words of memory => invalid address */
var acc = this.accessor; // get a local reference to the accessor object
this.E = eValue; // Just to show the world what's happening
switch (eValue) {
case 0x02: // A = [S]
acc.addr = this.S;
acc.MAIL = (this.S < 0x0200 && this.NCSF);
this.cc.fetch(acc);
this.A = acc.word;
this.AROF = 1;
break;
case 0x03: // B = [S]
acc.addr = this.S;
acc.MAIL = (this.S < 0x0200 && this.NCSF);
this.cc.fetch(acc);
this.B = acc.word;
this.BROF = 1;
break;
case 0x04: // A = [M]
acc.addr = this.M;
acc.MAIL = (this.M < 0x0200 && this.NCSF);
this.cc.fetch(acc);
this.A = acc.word;
this.AROF = 1;
break;
case 0x05: // B = [M]
acc.addr = this.M;
acc.MAIL = (this.M < 0x0200 && this.NCSF);
this.cc.fetch(acc);
this.B = acc.word;
this.BROF = 1;
break;
case 0x06: // M = [M].[18:15]
acc.addr = this.M;
acc.MAIL = (this.M < 0x0200 && this.NCSF);
this.cc.fetch(acc);
this.M = ((acc.word % 0x40000000) >>> 15) & 0x7FFF;
break;
case 0x0A: // [S] = A
acc.addr = this.S;
acc.MAIL = (this.S < 0x0200 && this.NCSF);
acc.word = this.A;
this.cc.store(acc);
break;
case 0x0B: // [S] = B
acc.addr = this.S;
acc.MAIL = (this.S < 0x0200 && this.NCSF);
acc.word = this.B;
this.cc.store(acc);
break;
case 0x0C: // [M] = A
acc.addr = this.M;
acc.MAIL = (this.M < 0x0200 && this.NCSF);
acc.word = this.A;
this.cc.store(acc);
break;
case 0x0D: // [M] = B
acc.addr = this.M;
acc.MAIL = (this.M < 0x0200 && this.NCSF);
acc.word = this.B;
this.cc.store(acc);
break;
case 0x30: // P = [C]
acc.addr = this.C;
acc.MAIL = (this.C < 0x0200 && this.NCSF);
this.cc.fetch(acc);
this.P = acc.word;
this.PROF = 1;
break;
default:
throw "Invalid E-register value: " + eValue.toString(2);
break;
}
this.cycleCount += B5500Processor.memCycles;
if (acc.MAED) {
this.I |= 0x02; // set I02F - memory address/inhibit error
if (this.NCSF || this !== this.cc.P1) {
this.cc.signalInterrupt();
} else {
this.busy = 0; // P1 invalid address in control state stops the proc
}
} else if (acc.MPED) {
this.I |= 0x01; // set I01F - memory parity error
if (this.NCSF || this !== this.cc.P1) {
this.cc.signalInterrupt();
} else {
this.busy = 0; // P1 memory parity in control state stops the proc
}
}
};
/**************************************/
B5500Processor.prototype.adjustAEmpty = function() {
/* Adjusts the A register so that it is empty, pushing the prior
contents of A into B and B into memory, as necessary. */
if (this.AROF) {
if (this.BROF) {
if ((this.S >>> 6) == this.R && this.NCSF) {
this.I |= 0x04; // set I03F: stack overflow
this.cc.signalInterrupt();
} else {
this.S++;
this.access(0x0B); // [S] = B
}
}
this.B = this.A;
this.AROF = 0;
this.BROF = 1;
// else we're done -- A is already empty
}
};
/**************************************/
B5500Processor.prototype.adjustAFull = function() {
/* Adjusts the A register so that it is full, popping the contents of
B or [S] into A, as necessary. */
if (!this.AROF) {
if (this.BROF) {
this.A = this.B;
this.AROF = 1;
this.BROF = 0;
} else {
this.access(0x02); // A = [S]
this.S--;
}
// else we're done -- A is already full
}
};
/**************************************/
B5500Processor.prototype.adjustBEmpty = function() {
/* Adjusts the B register so that it is empty, pushing the prior
contents of B into memory, as necessary. */
if (this.BROF) {
if ((this.S >>> 6) == this.R && this.NCSF) {
this.I |= 0x04; // set I03F: stack overflow
this.cc.signalInterrupt();
} else {
this.S++;
this.access(0x0B); // [S] = B
}
// else we're done -- B is already empty
}
};
/**************************************/
B5500Processor.prototype.adjustBFull = function() {
/* Adjusts the B register so that it is full, popping the contents of
[S] into B, as necessary. */
if (!this.BROF) {
this.access(0x03); // B = [S]
this.S--;
// else we're done -- B is already full
}
};
/**************************************/
B5500Processor.prototype.adjustABFull = function() {
/* Ensures both TOS registers are occupied, pushing up from memory as required */
if (this.AROF) {
if (this.BROF) {
// A and B are already full, so we're done
} else {
// A is full and B is empty, so load B from [S]
this.access(0x03); // B = [S]
this.S--;
}
} else {
if (this.BROF) {
// A is empty and B is full, so copy B to A and load B from [S]
this.A = this.B;
this.AROF = 1;
} else {
// A and B are empty, so simply load them from [S]
this.access(0x02); // A = [S]
this.S--;
}
this.access(0x03); // B = [S]
this.S--;
}
};
/**************************************/
B5500Processor.prototype.exchangeTOS = function() {
/* Exchanges the two top-of-stack values */
var temp;
if (this.AROF) {
if (this.BROF) {
// A and B are full, so simply exchange them
temp = this.A;
this.A = this.B;
this.B = temp;
} else {
// A is full and B is empty, so push A to B and load A from [S]
this.B = this.A;
this.BROF = 1;
this.access(0x02); // A = [S]
this.S--;
}
} else {
if (this.BROF) {
// A is empty and B is full, so copy B to A and load B from [S]
this.A = this.B;
this.AROF = 1;
this.access(0x03); // B = [S]
this.S--;
} else {
// A and B are empty, so simply load them in reverse order
this.access(0x03); // B = [S]
this.S--;
this.access(0x02); // A = [S]
this.S--;
}
}
};
/**************************************/
B5500Processor.prototype.jump = function(count, byWords) {
/* Adjusts the C and L registers by "count" (which may be negative).
If "byWords" is true, the adjustment is by words and L is set to 0.
Initiates a fetch to reload the P register after C and L are adjusted.
On entry, C and L are assumed to be pointing to the next instruction
to be executed, not the current one */
var addr;
if (byWords) {
this.C += count;
this.L = 0;
} else {
addr = this.C*4 + this.L + count;
this.C = addr >>> 2;
this.L = addr & 0x03;
}
this.access(0x30); // P = [C]
};
/**************************************/
B5500Processor.prototype.jumpOutOfLoop = function(count) {
/* Terminates the current character-mode loop by restoring the prior LCW
(or RCW) from the stack to X. If "count" is not zero, adjusts C & L forward
by that number of syllables and reloads P to branch to the jump-out location,
otherwise continues in sequence. Uses A to restore X and invalidates A */
var t1 = this.S; // save S (not the way the hardware did it)
this.cycleCount += 2;
this.S = this.cc.fieldIsolate(this.X, 18, 15); // get prior LCW addr from X value
this.access(0x02); // A = [S], fetch prior LCW from stack
if (count) {
this.cycleCount += (count >>> 2) + (count & 0x03);
this.jump(count, false);
}
this.X = this.A % 0x8000000000; // store prior LCW (39 bits: less control bits) in X
this.S = t1; // restore S
this.AROF = 0; // invalidate A
};
/**************************************/
B5500Processor.prototype.streamAdjustSourceChar = function() {
/* Adjusts the character-mode source pointer to the next character
boundary, as necessary. If the adjustment crosses a word boundary,
AROF is reset to force reloading later at the new source address */
if (this.H > 0) {
this.H = 0;
if (this.G < 7) {
this.G++;
} else {
this.G = 0;
this.AROF = 0;
this.M++;
}
}
};
/**************************************/
B5500Processor.prototype.streamAdjustDestChar = function() {
/* Adjusts the character-mode destination pointer to the next character
boundary, as necessary. If the adjustment crosses a word boundary and
BROF is set, B is stored at S before S is incremented and BROF is reset
to force reloading later at the new destination address */
if (this.V > 0) {
this.V = 0;
if (this.K < 7) {
this.K++;
} else {
this.K = 0;
if (this.BROF) {
this.access(0x0B); // [S] = B
this.BROF = 0;
}
this.S++;
}
}
};
/**************************************/
B5500Processor.prototype.compareSourceWithDest = function(count) {
/* Compares source characters to destination characters according to the
processor collating sequence.
"count" is the number of source characters to process.
The result of the comparison is left in two flip-flops:
Q03F=1: an inequality was detected
MSFF=1: the inequality was source > destination
If the two strings are equal, Q03F and MSFF will both be zero. Once an
inequality is encountered, Q03F will be set to 1 and MSFF (also known as
TFFF) will be set based on the nature of inequality. After this point, the
processor merely advances its address pointers to exhaust the count and does
not fetch additional words from memory. Note that the processor uses Q04F to
inhibit storing the B register at the end of a word boundary. This store
may be required only for the first word in the destination string, if B may
have been left in an updated state by a prior syllable */
var aBit; // A register bit nr
var bBit; // B register bit nr
this.MSFF = 0;
this.streamAdjustSourceChar();
this.streamAdjustDestChar();
if (count) {
if (this.BROF) {
if (this.K == 0) {
this.Q |= 0x08; // set Q04F -- at start of word, no need to store B later
}
} else {
this.access(0x03); // B = [S]
this.Q |= 0x08; // set Q04F -- just loaded B, no need to store it later
}
if (!this.AROF) {
this.access(0x04); // A = [M]
}
// setting Q06F and saving the count in H & V is only significant if this
// routine is executed as part of Field Add (FAD) or Field Subtract (FSU).
this.Q |= 0x20; // set Q06F
this.H = count >>> 3;
this.V = count & 0x07;
aBit = this.G*6; // A-bit number
bBit = this.K*6; // B-bit number
do {
this.cycleCount++; // approximate the timing
if (this.Q & 0x04) { // inequality already detected -- just count down
if (count >= 8) {
count -= 8;
if (!(this.Q & 0x08)) { // test Q04F to see if B may be dirty
this.access(0x0B); // [S] = B
this.Q |= 0x08; // set Q04F so we won't store B anymore
}
this.BROF = 0;
this.S++;
this.AROF = 0;
this.M++;
} else {
count--;
if (this.K < 7) {
this.K++;
} else {
if (!(this.Q & 0x08)) { // test Q04F to see if B may be dirty
this.access(0x0B); // [S] = B
this.Q |= 0x08; // set Q04F so we won't store B anymore
}
this.K = 0;
this.BROF = 0;
this.S++;
}
if (this.G < 7) {
this.G++;
} else {
this.G = 0;
this.AROF = 0;
this.M++;
}
}
} else { // strings still equal -- check this character
if ((this.Y = this.cc.fieldIsolate(this.A, aBit, 6)) != (this.Z = this.cc.fieldIsolate(this.B, bBit, 6))) {
this.Q |= 0x04; // set Q03F to stop further comparison
this.MSFF = (B5500Processor.collate[this.Y] > B5500Processor.collate[this.Z] ? 1 : 0);
} else { // strings still equal -- advance to next character
count--;
if (bBit < 42) {
bBit += 6;
this.K++;
} else {
bBit = 0;
this.K = 0;
if (!(this.Q & 0x08)) { // test Q04F to see if B may be dirty
this.access(0x0B); // [S] = B
this.Q |= 0x08; // set Q04F so we won't store B anymore
}
this.S++;
this.access(0x03); // B = [S]
}
if (aBit < 42) {
aBit += 6;
this.G++;
} else {
aBit = 0;
this.G = 0;
this.M++;
this.access(0x04); // A = [M]
}
}
}
} while (count);
}
};
/**************************************/
B5500Processor.prototype.fieldArithmetic = function(count, adding) {
/* Handles the Field Add (FAD) or Field Subtract (FSU) syllables.
"count" indicates the length of the fields to be operated upon.
"adding" will be false if this call is for FSU, otherwise it's for FAD */
var aBit; // A register bit nr
var bBit; // B register bit nr
var carry = 0; // carry/borrow bit
var compl = false; // complement addition (i.e., subtract the digits)
var MSFF = (this.MSFF != 0); // get TFFF as a Boolean
var Q03F = (this.Q & 0x04 != 0); // get Q03F as a Boolean
var resultNegative; // sign of result is negative
var sd; // digit sum
var ycompl = false; // complement source digits
var yd; // source digit
var zcompl = false; // complement destination digits
var zd; // destination digit
this.compareSourceWithDest(count);
this.cycleCount += 2; // approximate the timing thus far
if (this.Q & 0x20) { // Q06F => count > 0, so there's characters to add
this.Q &= ~(0x28); // reset Q06F and Q04F
// Back down the pointers to the last characters of their respective fields
if (this.K > 0) {
this.K--;
} else {
this.K = 7;
this.BROF = 0;
this.S--;
}
if (this.G > 0) {
this.G--;
} else {
this.G = 7;
this.AROF = 0;
this.M--;
}
if (!this.BROF) {
this.access(0x03); // B = [S]
}
if (!this.AROF) {
this.access(0x04); // A = [M]
}
this.Q |= 0x80; // set Q08F (for display only)
aBit = this.G*6; // A-bit number
bBit = this.K*6; // B-bit number
yd = this.cc.fieldIsolate(this.A, aBit, 2); // get the source sign
zd = this.cc.fieldIsolate(this.B, bBit, 2); // get the dest sign
compl = (yd == zd ? !adding : adding ); // determine if complement needed
resultNegative = !( // determine sign of result
(zd == 0 && !compl) ||
(zd == 0 && Q03F && !MSFF) ||
(zd != 0 && compl && Q03F && MSFF ) ||
(compl && !Q03F));
if (compl) {
this.Q |= 0x42; // set Q07F and Q02F (for display only)
carry = 1; // preset the carry/borrow bit (Q07F)
if (MSFF) {
this.Q |= 0x08; // set Q04F (for display only)
zcompl = true;
} else {
ycompl = true;
}
}
this.MSFF = 0; // reset TFFF so it can ultimately indicate overflow
this.cycleCount += 4;
do {
count--;
this.cycleCount += 2;
yd = this.cc.fieldIsolate(this.A, aBit+2, 4); // get the source sign
zd = this.cc.fieldIsolate(this.B, bBit+2, 4); // get the dest sign
sd = (ycompl ? 9-yd : yd) + (zcompl ? 9-zd : zd) + carry; // develop binary digit sum
if (sd <= 9) {
carry = this.MSFF = 0;
} else {
carry = this.MSFF = 1;
sd -= 10;
}
if (resultNegative) {
sd += 0x20; // set sign (BA) bits in char to binary 10
resultNegative = false;
}
this.cc.fieldInsert(this.B, bBit, 6, sd);
if (count == 0) {
this.access(0x0B); // [S] = B, store final dest word
} else {
if (bBit > 0) {
bBit -= 6;
this.K--;
} else {
bBit = 42;
this.K = 7;
this.access(0x0B); // [S] = B
this.S--;
this.access(0x03); // B = [S]
}
if (aBit > 0) {
aBit -= 6;
this.G--;
} else {
aBit = 42;
this.G = 7;
this.M--;
this.access(0x04); // A = [M]
}
}
} while (count);
// Now restore the character pointers
count = this.H*8 + this.V;
while (count >= 8) {
count -= 8;
this.cycleCount++;
this.S++;
this.M++;
}
this.cycleCount += count;
while (count > 0) {
count--;
if (this.K < 7) {
this.K++;
} else {
this.K = 0;
this.S++;
}
if (this.G < 7) {
this.G++;
} else {
this.G = 0;
this.M++;
}
}
this.AROF = this.BROF = 0;
this.H = this.V = this.N = 0;
}
};
/**************************************/
B5500Processor.prototype.streamBitsToDest = function(count, mask) {
/* Streams a pattern of bits to the destination specified by S, K, and V,
as supplied by the 48-bit "mask" argument. Partial words are filled from
the low-order bits of the mask. Implements the guts of Character-Mode
Bit Set (XX64) and Bit Reset (XX65). Leaves the registers pointing at the
next bit in sequence */
var bn; // field starting bit number
var fl; // field length in bits
if (count) {
this.cycleCount += count;
if (!this.BROF) {
this.access(0x03); // B = [S]
}
do {
bn = this.K*6 + this.V; // starting bit nr.
fl = 48-bn; // bits remaining in the word
if (count < fl) {
fl = count;
}
if (fl < 48) {
this.B = this.cc.fieldInsert(this.B, bn, fl, mask);
} else {
this.B = mask; // set the whole word
}
count -= fl; // decrement by number of bits modified
bn += fl; // increment the starting bit nr.
if (bn < 48) {
this.V = bn % 6;
this.K = (bn - this.V)/6;
} else {
this.K = this.V = 0;
this.access(0x0B); // [S] = B, save the updated word
this.S++;
if (count > 0) {
this.access(0x03); // B = [S], fetch next word in sequence
} else {
this.BROF = 0;
}
}
} while (count);
}
};
/**************************************/
B5500Processor.prototype.streamSourceToDest = function(count, transform) {
/* General driver for character-mode character transfers from source to
destination, such as TRS or TRZ.
"count" is the number of source characters to transfer.
"transform" is a function(bBit, count) that determines how the characters
are transferred from the source (A) to destination (B). The Y register will
contain the current char during this call */
var aBit; // A register bit nr
var bBit; // B register bit nr
this.streamAdjustSourceChar();
this.streamAdjustDestChar();
if (count) {
if (!this.BROF) {
this.access(0x03); // B = [S]
}
if (!this.AROF) {
this.access(0x04); // A = [M]
}
this.cycleCount += count; // approximate the timing
aBit = this.G*6; // A-bit number
bBit = this.K*6; // B-bit number
do {
this.Y = this.cc.fieldIsolate(this.A, aBit, 6);
transform(bBit, count)
count--;
if (bBit < 42) {
bBit += 6;
this.K++;
} else {
bBit = 0;
this.K = 0;
this.access(0x0B); // [S] = B
this.S++;
if (count < 8) { // only need to load B if a partial word is left
this.access(0x03); // B = [S]
}
}
if (aBit < 42) {
aBit += 6;
this.G++;
} else {
aBit = 0;
this.G = 0;
this.M++;
this.access(0x04); // A = [M]
}
} while (count)
}
};
/**************************************/
B5500Processor.prototype.streamToDest = function(count, transform) {
/* General driver for character-mode character operations on the destination
from a non-A register source, such as TBN.
"count" is the number of characters to transfer.
"transform" is a function(bBit, count) that determines how the characters
are stored to the destination (B). Returning truthy terminates the process
without incrementing the destination address */
var bBit; // B register bit nr
this.streamAdjustDestChar();
if (count) {
if (!this.BROF) {
this.access(0x03); // B = [S]
}
this.cycleCount += count; // approximate the timing
bBit = this.K*6; // B-bit number
do {
if (transform(bBit, count)) {
count = 0;
} else {
count--;
if (bBit < 42) {
bBit += 6;
this.K++;
} else {
bBit = 0;
this.K = 0;
this.access(0x0B); // [S] = B
this.S++;
if (count < 8) { // only need to reload B if a partial word is left
this.access(0x03); // B = [S]
}
}
}
} while (count)
}
};
/**************************************/
B5500Processor.prototype.streamInputConvert = function(count) {
/* Converts a signed-numeric character field at the source M & G address
from decimal to binary, storing the resulting word at the S address and then
incrementing S. Normally, decimal to binary conversion shouldn't be this
complex, so we must do it more or less the way the B5500 hardware did, by
repeated remainder division (i.e., shifting right) and adjusting the
low-order digit by -3 when a one was shifted into the high-order bit of the
low-order digit from the higher digit locations. The problem with doing it a
more direct and efficient way is with digits that are not in the range 0-9.
Doing it the hardware way should yield the same (albeit questionable)
result. See Section 2.6 in the B5281 Training Manual for details. This
process took at least 27 clocks on the B5500, so we can afford to be slow
here, too. Note that a maximum of 8 characters are converted */
var a = 0; // local working copy of A
var b = 0; // local working copy of B
var power = 1; // A-register shif factor
this.streamAdjustSourceChar();
if (this.BROF) {
this.access(0x0B); // [S] = B
this.BROF = 0;
}
if (this.K || this.V) { // adjust dest to word boundary
this.K = this.V = 0;
this.S++;
}
if (count) { // count > 0
this.cycleCount += count*2 + 27;
count = ((count-1) & 0x07) + 1; // limit the count to 8
if (!this.AROF) {
this.access(0x04); // A = [M]
}
// First, assemble the digits into B
do {
b = b << 4 | ((this.Y = this.cc.fieldIsolate(this.A, this.G*6, 6)) & 0x0F);
if (this.G < 7) {
this.G++;
} else {
this.G = 0;
this.M++;
if (count > 1) {
this.access(0x04); // A = [M], only if more chars are needed
} else {
this.AROF = 0;
}
}
} while (--count);
// Then do the artful shifting to form the binary value in A
this.AROF = 0;
this.B = b; // for display purposes only
while (b) {
if (b & 0x01) {
a += power;
}
power *= 2;
b >>>= 1;
if (b & 0x08) {
b -= 3; // since the low-order digit is >= 8, don't worry about borrow
}
}
// Finally, fix up the binary sign and store the result
if (a) { // zero results have sign bit reset
if (this.Y & 0x30 == 0x20) {
a += 0x400000000000; // set the sign bit
}
}
this.A = a;
this.access(0x0A); // [S] = A
this.S++;
}
};
/**************************************/
B5500Processor.prototype.streamOutputConvert = function(count) {
/* Converts the binary word addressed by M (after word-boundary adjustment)
to decimal BIC at the destination address of S & K. The maximum number of
digits to convert is 8. If the binary value can be represented in "count"
digits (or the count is zero), the true-false FF, MSFF, is set; otherwise it
is reset. The sign is stored in low-order character of the result */
var a; // local working copy of A
var b = 0; // local working copy of B
var c; // converted decimal character
var d = 0; // digit counter
var power = 1; // power-of-64 factor for result digits
this.MSFF = 1; // set TFFF unless there's overflow
this.streamAdjustDestChar();
if (this.BROF) {
this.access(0x0B); // [S] = B, but leave BROF set
}
if (this.G || this.H) { // adjust source to word boundary
this.G = this.H = 0;
this.AROF = 0;
this.M++;
}
if (count) { // count > 0
this.cycleCount += count*2 + 27;
if (!this.AROF) {
this.access(0x04); // A = [M]
}
count = ((count-1) & 0x07) + 1; // limit the count to 8
a = this.A % 0x8000000000; // get absolute mantissa value, ignore exponent
if (a) { // mantissa is non-zero, so conversion is required
if ((this.A % 0x800000000000) >= 0x400000000000) {
b = 0x20; // result is negative, so preset the sign in the low-order digit
}
do { // Convert the binary value in A to BIC digits in B
c = a % 10;
a = (a-c)/10;
if (c) {
b += c*power;
}
power *= 64;
} while (a && ++d < count);
if (a) {
this.MSFF = 0; // overflow occurred, so reset TFFF
}
}
this.AROF = 0; // invalidate A
this.M++; // and advance to the next source word
// Finally, stream the digits from A (whose value is still in local b) to the destination
this.A = b; // for display purposes only
this.access(0x03) // B = [S], restore original value of B
d = 48 - count*6; // starting bit in A
do {
this.B = this.cc.fieldTransfer(this.B, this.K*6, 6, b, d);
d += 6;
if (this.K < 7) {
this.K++;
} else {
this.access(0x0B); // [S] = B
this.K = 0;
this.S++;
if (count > 1) {
this.access(0x03); // B = [S]
} else {
this.BROF = 0;
}
}
} while (--count);
}
};
/**************************************/
B5500Processor.prototype.storeForInterrupt = function(forTest) {
/* Implements the 3011=SFI operator and the parts of 3411=SFT that are
common to it. "forTest" implies use from SFT */
var forced = this.Q & 0x40; // Q07F: Hardware-induced SFI syllable
var saveAROF = this.AROF;
var saveBROF = this.BROF;
var temp;
if (forced || forTest) {
this.NCSF = 0; // switch to control state
}
if (this.CWMF) {
temp = this.S; // get the correct TOS address from X
this.S = (this.X % 0x40000000) >>> 15;
this.X = this.cc.fieldInsert(this.X, 18, 15, temp);
if (this.AROF || forTest) {
this.S++;
this.access(0x0A); // [S] = A
}
if (this.BROF || forTest) {
this.S++;
this.access(0x0B); // [S] = B
}
this.B = this.X + // store CM loop-control word
saveAROF * 0x200000000000 +
0xC00000000000;
this.S++;
this.access(0x0B); // [S] = B
} else {
if (this.BROF || forTest) {
this.S++;
this.access(0x0B); // [S] = B
}
if (this.AROF || forTest) {
this.S++;
this.access(0x0A); // [S] = A
}
}
this.B = this.M + // store interrupt control word (ICW)
this.N * 0x8000 +
this.VARF * 0x1000000 +
this.SALF * 0x40000000 +
this.MSFF * 0x80000000 +
this.R * 0x200000000 +
0xC00000000000;
this.S++;
this.access(0x0B); // [S] = B
this.B = this.C + // store interrupt return control word (IRCW)
this.F * 0x8000 +
this.K * 0x40000000 +
this.G * 0x200000000 +
this.L * 0x1000000000 +
this.V * 0x4000000000 +
this.H * 0x20000000000 +
saveBROF * 0x200000000000 +
0xC00000000000;
this.S++;
this.access(0x0B); // [S] = B
if (this.CWMF) {
temp = this.F; // if CM, get correct R value from last MSCW
this.F = this.S;
this.S = temp;
this.access(0x03); // B = [S]: get last RCW
this.S = ((this.B % 0x40000000) >>> 15) & 0x7FFF;
this.access(0x03); // B = [S]: get last MSCW
this.R = this.cc.fieldIsolate(this.B, 6, 9);
this.S = this.F;
}
this.B = this.S + // store the initiate control word (INCW)
this.CWMF * 0x8000 +
0xC00000000000;
if (forTest) {
this.B += (this.TM & 0x1F) * 0x10000 +
this.Z * 0x400000 +
this.Y * 0x10000000 +
(this.Q & 0x1FF) * 0x400000000;
this.TM = 0;
this.MROF = 0;
this.MWOF = 0;
}
this.M = (this.R*64) + 0x08; // store initiate word at R+@10
this.access(0x0D); // [M] = B
this.M = 0;
this.R = 0;
this.MSFF = 0;
this.SALF = 0;
this.BROF = 0;
this.AROF = 0;
if (forced) {
if (this === this.cc.P1) {
this.T = 0x89; // inject 0211=ITI into T register
} else {
this.T = 0; // idle the processor
this.TROF = 0;
this.PROF = 0;
this.busy = 0;
this.cc.HP2F = 1;
this.cc.P2BF = 0; // tell P1 we've stopped
if (this.scheduler) {
clearTimeout(this.scheduler);
this.scheduler = null;
}
}
this.CWMF = 0;
} else if (forTest) {
this.CWMF = 0;
if (this === this.cc.P1) {
this.access(0x05); // B = [M]: load DD for test
this.C = this.B % 0x7FFF;
this.L = 0;
this.access(0x30); // P = [C]: first word of test routine
this.G = 0;
this.H = 0;
this.K = 0;
this.V = 0;
} else {
this.T = 0; // idle the processor
this.TROF = 0;
this.PROF = 0;
this.busy = 0;
this.cc.HP2F = 1;
this.cc.P2BF = 0; // tell P1 we've stopped
if (this.scheduler) {
clearTimeout(this.scheduler);
this.scheduler = null;
}
}
}
};
/**************************************/
B5500Processor.prototype.start = function() {
/* Initiates the processor from a load condition at P=@20 */
this.C = runAddr; // starting execution address
this.access(0x30); // P = [C]
this.T = this.fieldIsolate(this.P, 0, 12);
this.TROF = 1;
this.L = 1; // advance L to the next syllable
// Now start scheduling the processor on the Javascript thread
this.busy = 1;
this.procTime = new Date().getTime()*1000;
this.scheduler = setTimeout(this.schedule, 0);
};
/**************************************/
B5500Processor.prototype.initiate = function(forTest) {
/* Initiates the processor from interrupt control words stored in the
stack. Assumes the INCW is in A. "forTest" implies use from IFT */
var saveAROF;
var saveBROF;
var temp;
// restore the Initiate Control Word or Initiate Test Control Word
this.S = this.A % 0x8000;
this.CWMF = Math.floor(this.A / 0x8000) % 0x02;
if (forTest) {
this.TM = Math.floor(this.A / 0x10000) % 0x20;
this.Z = Math.floor(this.A / 0x400000) % 0x40;
this.Y = Math.floor(this.A / 0x10000000) % 0x40;
this.Q = Math.floor(this.A / 0x400000000) % 0x200;
this.TM |= Math.floor(this.A / 0x200000) % 0x02 * 32; // CCCF
this.TM |= Math.floor(this.A / 0x80000000000) % 0x02 * 64; // MWOF
this.TM |= Math.floor(this.A / 0x400000000000) % 0x02 * 128; // MROF
// Emulator doesn't support J register, so can't set that from TM
}
this.AROF = 0;
this.BROF = 0;
// restore the Interrupt Return Control Word
this.access(0x03); // B = [S]
this.S--;
this.C = this.B % 0x8000;
this.F = Math.floor(this.B / 0x8000) % 0x8000;
this.K = Math.floor(this.B / 0x40000000) % 0x08;
this.G = Math.floor(this.B / 0x200000000) % 0x08;
this.L = Math.floor(this.B / 0x1000000000) % 0x04;
this.V = Math.floor(this.B / 0x4000000000) % 0x08;
this.H = Math.floor(this.B / 0x20000000000) % 0x08;
this.access(0x30); // P = [C]
if (this.CWMF || forTest) {
saveBROF = Math.floor(this.B / 200000000000) % 0x02;
}
// restore the Interrupt Control Word
this.access(0x03); // B = [S]
this.S--;
this.VARF = Math.floor(this.B / 0x1000000) % 0x02;
this.SALF = Math.floor(this.B / 0x40000000) % 0x02;
this.MSFF = Math.floor(this.B / 0x80000000) % 0x02;
this.R = (Math.floor(this.B / 0x200000000) % 0x200);
if (this.CWMF || forTest) {
this.M = this.B % 0x8000;
this.N = Math.floor(this.B / 0x8000) % 0x10;
// restore the CM Interrupt Loop Control Word
this.access(0x03); // B = [S]
this.S--;
this.X = this.B % 0x8000000000;
saveAROF = Math.floor(this.B / 0x400000000000) % 0x02;
// restore the B register
if (saveBROF || forTest) {
this.access(0x03); // B = [S]
this.S--;
}
// restore the A register
if (saveAROF || forTest) {
this.access(0x02); // A = [S]
this.S--;
}
if (this.CWMF) {
// exchange S with its field in X
temp = this.S;
this.S = (this.X % 0x40000000) >>> 15;
this.X = this.X % 0x8000 +
temp * 0x8000 +
Math.floor(this.X / 0x40000000) * 0x40000000;
}
// else don't restore A or B for word mode -- will pop up as necessary
}
this.T = this.cc.fieldIsolate(this.P, this.L*12, 12);
this.TROF = 1;
if (forTest) {
this.NCSF = (this.TM >>> 4) & 0x01;
this.CCCF = (this.TM >>> 5) & 0x01;
this.MWOF = (this.TM >>> 6) & 0x01;
this.MROF = (this.TM >>> 7) & 0x01;
this.S--;
if (!this.CCCF) {
this.TM |= 0x80;
}
} else {
this.NCSF = 1;
this.busy = 1;
}
};
/**************************************/
B5500Processor.prototype.initiateAsP2 = function() {
/* Called from Central Control to initiate the processor as P2. Fetches the
INCW from @10 and calls initiate() */
this.M = 0x08; // address of the INCW
this.access(0x04); // A = [M]
this.AROF = 1;
this.T = 0x849; // inject 4111=IP1 into P2's T register
this.TROF = 1;
this.NCSF = 0; // make sure P2 is in control state
// Now start scheduling P2 on the Javascript thread
this.procTime = new Date().getTime()*1000;
this.scheduler = setTimeout(this.schedule, 0);
};
/**************************************/
B5500Processor.prototype.singlePrecisionCompare = function() {
/* Algebraically compares the B register to the A register. Function returns
-1 if B<A, 0 if B=A, or +1 if B>A. Exits with AROF=0, BROF=1, and A and B as is */
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A
var mb; // absolute mantissa of B
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
this.cycleCount += 4; // estimate some general overhead
this.adjustABFull();
this.AROF = 0; // A is unconditionally marked empty
ma = this.A % 0x8000000000; // extract the A mantissa
mb = this.B % 0x8000000000; // extract the B mantissa
// Extract the exponents and signs. If the exponents are unequal, normalize
// each until the high-order octade is non-zero or the exponents are equal.
if (ma == 0) { // if A mantissa is zero
ea = sa = 0; // consider A to be completely zero
} else {
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
while (ma < 0x1000000000 && ea != eb) {
this.cycleCount++;
ma *= 8; // shift left
ea--;
}
}
if (mb == 0) { // if B mantissa is zero
eb = sb = 0; // consider B to be completely zero
} else {
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
while (mb < 0x1000000000 && eb != ea) {
this.cycleCount++;
mb *= 8; // shift left
eb--;
}
}
// Compare signs, exponents, and normalized magnitudes, in that order.
if (sb == sa) { // if signs are equal:
if (eb == ea) { // if exponents are equal:
if (mb = ma) { // if magnitudes are equal:
return 0; // then the operands are equal
} else if (mb > ma) { // otherwise, if magnitude of B > A:
return (sb ? -1 : 1); // B<A if B negative, B>A if B positive
} else { // otherwise, if magnitude of B < A:
return (sb ? 1 : -1); // B>A if B negative, B<A if B positive
}
} else if (eb > ea) { // otherwise, if exponent of B > A:
return (sb ? -1 : 1); // B<A if B negative, B>A if B positive
} else { // otherwise, if exponent of B < A
return (sb ? 1 : -1); // B>A if B negative, B<A if B positive
}
} else { // otherwise, if signs are different:
return (sa < sb ? -1 : 1); // B<A if B negative, B>A if B positive
}
};
/**************************************/
B5500Processor.prototype.singlePrecisionAdd = function(adding) {
/* Adds the contents of the A register to the B register, leaving the result
in B and invalidating A. If "adding" is not true, the sign of A is complemented
to accomplish subtraction instead of addition */
var d = 0; // the guard (rounding) digit
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A*8
var mb; // absolute mantissa of B*8
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
var xx = 0; // local copy of X
this.cycleCount += 4; // estimate some general overhead
this.adjustABFull();
this.AROF = 0; // A is unconditionally marked empty
ma = this.A % 0x8000000000; // extract the A mantissa
mb = this.B % 0x8000000000; // extract the B mantissa
if (ma == 0) { // if A mantissa is zero
if (mb == 0) { // and B mantissa is zero
this.B = 0; // result is all zeroes
} else {
this.B %= 0x800000000000; // otherwise, result is B with flag bit reset
}
} else if (mb == 0 && adding) { // otherwise, if B is zero and we're adding,
this.B = this.A % 0x800000000000; // result is A with flag bit reset
} else { // rats, we actually have to do this
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
// If the exponents are unequal, normalize the larger and scale the smaller
// until they are in alignment, or one of the mantissas (mantissae?) becomes zero
if (ea > eb) {
// Normalize A for 39 bits (13 octades)
while (ma < 0x1000000000 && ea != eb) {
this.cycleCount++;
ma *= 8; // shift left
ea--;
}
// Scale B until its exponent matches or mantissa goes to zero
while (ea != eb) {
this.cycleCount++;
d = mb % 8;
mb = (mb - d)/8; // shift right into X
xx = (xx - xx%8)/8 + d*0x1000000000;
if (mb) {
eb++;
} else {
eb = ea; // if B=0, result will have exponent of A
// should we clear X at this point to prevent rounding of A?
}
}
} else if (ea < eb) {
// Normalize B for 39 bits (13 octades)
while (mb < 0x1000000000 && eb != ea) {
this.cycleCount++;
mb *= 8; // shift left
eb--;
}
// Scale A until its exponent matches or mantissa goes to zero
while (eb != ea) {
this.cycleCount++;
d = ma % 8;
ma = (ma -d)/8; // shift right into X
xx = (xx - xx%8)/8 + d*0x1000000000;
if (ma) {
ea++;
} else {
ea = eb; // if A=0, kill the scaling loop
// should we clear X at this point to prevent rounding of B?
}
}
}
// At this point, the exponents are aligned (or one of the mantissas
// is zero), so do the actual 39-bit addition
mb = (sb ? -mb : mb) + (sa ^ (adding ? 0 : 1) ? -ma : ma);
if (mb == 0) {
this.B = 0;
} else {
// Determine the resulting sign
if (mb >= 0) {
sb = 0;
} else {
sb = 1;
mb = -mb;
}
// Normalize and round as necessary
if (mb < 0x1000000000 && xx >= 0x800000000) { // Normalization can be required for subtract
this.cycleCount++;
d = (xx - xx%0x1000000000)/0x1000000000; // get the rounding digit from X
xx = (xx%0x1000000000)*8; // shift B and X left together
mb = mb*8 + d;
eb--;
d = (xx - xx%0x1000000000)/0x1000000000; // get the next rounding digit from X
} else if (mb >= 0x8000000000) { // Scaling can be required for add
this.cycleCount++;
d = mb % 8; // get the rounding digit from B
mb = (mb - d)/8; // shift right due to overflow
eb++;
}
// Note: the Training Manual does not say that rounding is suppressed
// for add/subtract when the mantissa is all ones, but it does say so
// for multiply/divide, so we assume it's also the case here.
if (d & 0x04) { // if the guard digit >= 4
if (mb < 0x7FFFFFFFFF) {// and rounding would not cause overflow
this.cycleCount++;
mb++; // round up the result
}
}
// Check for exponent overflow
if (eb > 63) {
eb %= 64;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xB0; // set I05/6/8: exponent-overflow
this.cc.signalInterrupt();
}
} else if (eb < 0) {
eb = (-eb) | 0x40; // set the exponent sign bit
}
this.X = xx; // for display purposes only
this.B = (sb*128 + eb)*0x8000000000 + mb; // Final Answer
}
}
};
/**************************************/
B5500Processor.prototype.singlePrecisionMultiply = function() {
/* Multiplies the contents of the A register to the B register, leaving the
result in B and invalidating A. A double-precision mantissa is developed and
then normalized and rounded */
var d; // current multiplier digit (octal)
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A
var mb; // absolute mantissa of B
var mx = 0; // local copy of X for product extension
var n = 0; // local copy of N (octade counter)
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
var xx; // local copy of X for multiplier
this.cycleCount += 4; // estimate some general overhead
this.adjustABFull();
this.AROF = 0; // A is unconditionally marked empty
ma = this.A % 0x8000000000; // extract the A mantissa
mb = this.B % 0x8000000000; // extract the B mantissa
if (ma == 0) { // if A mantissa is zero
this.B = 0; // result is all zeroes
} else if (mb == 0) { // otherwise, if B is zero,
this.B = 0; // result is all zeroes
} else { // otherwise, let the games begin
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
// If the exponents are BOTH zero, perform an integer multiply.
// Otherwise, normalize both operands
if (ea == 0 && eb == 0) {
this.Q |= 0x10; // integer multiply operation: set Q05F
} else {
// Normalize A for 39 bits (13 octades)
while (ma < 0x1000000000) {
this.cycleCount++;
ma *= 8; // shift left
ea--;
}
// Normalize B for 39 bits (13 octades)
while (mb < 0x1000000000) {
this.cycleCount++;
mb *= 8; // shift left
eb--;
}
}
// Determine resulting mantissa sign; initialize the product
sb ^= sa; // positive if signs are same, negative if different
xx = mb; // move multiplier to X
mb = 0; // initialize high-order part of product
// Now we step through the 13 octades of the multiplier, developing the product
do {
d = xx % 8; // extract the current multiplier digit
xx = (xx - d)/8; // shift the multiplier right one octade
if (d == 0) { // if multiplier digit is zero
this.cycleCount++; // hardware optimizes this case
} else {
this.cycleCount += 3; // just estimate the average number of clocks
mb += ma*d; // develop the partial product
}
d = mb % 8; // get the low-order octade of partial product in B
mb = (mb - d)/8; // shift B right one octade
mx = mx/8 + d*0x1000000000; // shift B octade into high-order end of extension
} while (++n < 13);
// Normalize the result
if (this.Q & 0x10 && mb == 0) { // if it's integer multiply (Q05F) with integer result
mb = mx; // just use the low-order 39 bits
eb = 0; // and don't normalize
} else {
eb += ea+13; // compute resulting exponent from multiply
while (mb < 0x1000000000) {
this.cycleCount++;
ma = mx % 0x1000000000; // reuse ma: get low-order 36 bits of mantissa extension
d = (mx - ma)/0x1000000000; // get high-order octade of extension
mb = mb*8 + d; // shift high-order extension octade into B
mx = ma*8; // shift extension left one octade
eb--;
}
}
// Round the result
this.Q &= ~(0x10); // reset Q05F
this.A = 0; // required by specs due to the way rounding addition worked
if (xx >= 0x4000000000) { // if high-order bit of remaining extension is 1
this.Q |= 0x01 // set Q01F (for display purposes only)
if (mb < 0x7FFFFFFFFF) { // if the rounding would not cause overflow
this.cycleCount++;
mb++; // round up the result
}
}
if (mb == 0) { // don't see how this could be necessary here, but
this.B = 0; // the TM says to do it anyway
} else {
// Check for exponent under/overflow
if (eb > 63) {
eb %= 64;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xB0; // set I05/6/8: exponent-overflow
this.cc.signalInterrupt();
}
} else if (eb < -63) {
eb = ((-eb) % 64) | 0x40; // mod the exponent and set its sign
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xA0; // set I06/8: exponent-underflow
this.cc.signalInterrupt();
}
} else if (eb < 0) {
eb = (-eb) | 0x40; // set the exponent sign bit
}
this.B = (sb*128 + eb)*0x8000000000 + mb; // Final Answer
}
}
this.X = mx; // for display purposes only
};
/**************************************/
B5500Processor.prototype.singlePrecisionDivide = function() {
/* Divides the contents of the A register into the B register, leaving the
result in B and invalidating A. A 14-octade mantissa is developed and
then normalized and rounded */
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A
var mb; // absolute mantissa of B
var n = 0; // local copy of N (octade counter)
var q = 0; // current quotient digit (octal)
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
var xx = 0; // local copy of X for quotient development
this.cycleCount += 4; // estimate some general overhead
this.adjustABFull();
this.AROF = 0; // A is unconditionally marked empty
ma = this.A % 0x8000000000; // extract the A mantissa
mb = this.B % 0x8000000000; // extract the B mantissa
if (ma == 0) { // if A mantissa is zero
this.A = this.B = 0; // result is all zeroes
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xD0; // set I05/7/8: divide by zero
this.cc.signalInterrupt();
}
} else if (mb == 0) { // otherwise, if B is zero,
this.A = this.B = 0; // result is all zeroes
} else { // otherwise, may the octades always be in your favor
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
// Normalize A for 39 bits (13 octades)
while (ma < 0x1000000000) {
this.cycleCount++;
ma *= 8; // shift left
ea--;
}
// Normalize B for 39 bits (13 octades)
while (mb < 0x1000000000) {
this.cycleCount++;
mb *= 8; // shift left
eb--;
}
sb ^= sa; // positive if signs are same, negative if different
// Now we step through the development of the quotient one octade at a time,
// tallying the shifts in n until the high-order octade of xx is non-zero (i.e.,
// normalized). The divisor is in ma and the dividend (which becomes the
// remainder) is in mb. Since the operands are normalized, this will take
// either 13 or 14 shifts. We do the xx shift at the top of the loop so that
// the 14th (rounding) digit will be available in q at the end. The initial
// shift has no effect, as it operates using zero values for xx and q.
do {
xx = xx*8 + q; // shift quotient digit into the working quotient
n++; // tally the shifts (one more than affects result)
q = 0; // initialize the quotient digit
while (mb >= ma) {
q++; // bump the quotient digit
mb -= ma; // subtract divisor from remainder
}
mb *= 8; // shift the remainder left one octade
} while (xx < 0x1000000000);
this.cycleCount += n*3; // just estimate the average number of divide clocks
eb -= ea + n - 2; // compute the exponent, accounting for the extra shift
// Round the result (it's already normalized)
this.A = 0; // required by specs due to the way rounding addition worked
if (q >= 4) { // if high-order bit of last quotient digit is 1
this.Q |= 0x01 // set Q01F (for display purposes only)
if (xx < 0x7FFFFFFFFF) { // if the rounding would not cause overflow
xx++; // round up the result
}
}
// Check for exponent under/overflow
if (eb > 63) {
eb %= 64;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xB0; // set I05/6/8: exponent-overflow
this.cc.signalInterrupt();
}
} else if (eb < -63) {
eb = ((-eb) % 64) | 0x40; // mod the exponent and set its sign
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xA0; // set I06/8: exponent-underflow
this.cc.signalInterrupt();
}
} else if (eb < 0) {
eb = (-eb) | 0x40; // set the exponent sign bit
}
this.B = (sb*128 + eb)*0x8000000000 + xx; // Final Answer
}
this.X = xx; // for display purposes only
};
/**************************************/
B5500Processor.prototype.integerDivide = function() {
/* Divides the contents of the A register into the B register, leaving the
integerized result in B and invalidating A. If the result cannot be expressed
as an integer, the Integer-Overflow interrupt is set */
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A
var mb; // absolute mantissa of B
var n = 0; // local copy of N (octade counter)
var q = 0; // current quotient digit (octal)
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
var xx = 0; // local copy of X for quotient development
this.cycleCount += 4; // estimate some general overhead
this.adjustABFull();
this.AROF = 0; // A is unconditionally marked empty
ma = this.A % 0x8000000000; // extract the A mantissa
mb = this.B % 0x8000000000; // extract the B mantissa
if (ma == 0) { // if A mantissa is zero
this.A = this.B = 0; // result is all zeroes
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xD0; // set I05/7/8: divide by zero
this.cc.signalInterrupt();
}
} else if (mb == 0) { // otherwise, if B is zero,
this.A = this.B = 0; // result is all zeroes
} else { // otherwise, continue
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
// Normalize A for 39 bits (13 octades)
while (ma < 0x1000000000) {
this.cycleCount++;
ma *= 8; // shift left
ea--;
}
// Normalize B for 39 bits (13 octades)
while (mb < 0x1000000000) {
this.cycleCount++;
mb *= 8; // shift left
eb--;
}
if (ea > eb) { // if divisor has greater magnitude
this.A = this.B = 0; // quotient is < 1, so set result to zero
} else { // otherwise, do the long division
sb ^= sa; // positive if signs are same, negative if different
// Now we step through the development of the quotient one octade at a time,
// similar to that for DIV, but in addition to stopping when the high-order
// octade of xx is non-zero (i.e., normalized), we can stop if the exponents
// becomes equal. Since there is no rounding, we do not need to develop an
// extra quotient digit.
do {
this.cycleCount += 3; // just estimate the average number of clocks
q = 0; // initialize the quotient digit
while (mb >= ma) {
q++; // bump the quotient digit
mb -= ma; // subtract divisor from remainder
}
mb *= 8; // shift the remainder left one octade
xx = xx*8 + q; // shift quotient digit into the working quotient
if (xx >= 0x1000000000) {
break; // quotient has become normalized
} else if (ea < eb) {
eb--; // decrement the B exponent
} else {
break;
}
} while (true);
if (ea == eb) {
eb = 0; // integer result developed
} else {
if (this.NCSF) { // integer overflow result
this.I = (this.I & 0x0F) | 0xC0; // set I07/8: integer-overflow
this.cc.signalInterrupt();
}
eb = (eb-ea)%64;
if (eb < 0) {
eb = (-eb) | 0x40; // set the exponent sign bit
}
}
this.A = 0; // required by specs
this.B = (sb*128 + eb)*0x8000000000 + xx; // Final Answer
}
}
this.X = xx; // for display purposes only
};
/**************************************/
B5500Processor.prototype.remainderDivide = function() {
/* Divides the contents of the A register into the B register, leaving the
remainder result in B and invalidating A. The sign of the result is the sign
of the dividend (B register value). If the quotient cannot be expressed as an
integer, the Integer-Overflow interrupt is set */
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A
var mb; // absolute mantissa of B
var n = 0; // local copy of N (octade counter)
var q = 0; // current quotient digit (octal)
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
var xx = 0; // local copy of X for quotient development
this.cycleCount += 4; // estimate some general overhead
this.adjustABFull();
this.AROF = 0; // A is unconditionally marked empty
ma = this.A % 0x8000000000; // extract the A mantissa
mb = this.B % 0x8000000000; // extract the B mantissa
if (ma == 0) { // if A mantissa is zero
this.A = this.B = 0; // result is all zeroes
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xD0; // set I05/7/8: divide by zero
this.cc.signalInterrupt();
}
} else if (mb == 0) { // otherwise, if B is zero,
this.A = this.B = 0; // result is all zeroes
} else { // otherwise, continue
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
// Normalize A for 39 bits (13 octades)
while (ma < 0x1000000000) {
this.cycleCount++;
ma *= 8; // shift left
ea--;
}
// Normalize B for 39 bits (13 octades)
while (mb < 0x1000000000) {
this.cycleCount++;
mb *= 8; // shift left
eb--;
}
if (ea > eb) { // if divisor has greater magnitude
this.A = 0; // quotient is < 1, so set A to zero and
this.B %= 0x8000000000000; // result is original B (less the flag bit)
} else { // otherwise, work remains (so to speak)
// Now we step through the development of the quotient one octade at a time,
// similar to that for DIV, but in addition to stopping when the high-order
// octade of xx is non-zero (i.e., normalized), we can stop if the exponents
// becomes equal. Since there is no rounding, we do not need to develop an
// extra quotient digit.
do {
this.cycleCount += 3; // just estimate the average number of clocks
q = 0; // initialize the quotient digit
while (mb >= ma) {
q++; // bump the quotient digit
mb -= ma; // subtract divisor from remainder
}
xx = xx*8 + q; // shift quotient digit into the working quotient
if (xx >= 0x1000000000) {
break; // quotient has become normalized
} else if (ea < eb) {
mb *= 8; // shift the remainder left one octade
eb--; // decrement the B exponent
} else {
break;
}
} while (true);
if (eb < -63) { // check for exponent underflow
eb %= 64; // if so, exponent is mod 64
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xA0; // set I06/8: exponent-underflow
this.cc.signalInterrupt();
}
} else if (ea == eb) { // integer result developed
if (mb == 0) { // if B mantissa is zero, then
eb = sb = 0; // assure result will be all zeroes
} else {
eb %= 64; // use remainder exponent mod 64
}
} else {
if (this.NCSF) { // integer overflow result
this.I = (this.I & 0x0F) | 0xC0; // set I07/8: integer-overflow
this.cc.signalInterrupt();
}
mb = eb = sb = 0; // result in B will be all zeroes
}
if (eb < 0) {
eb = (-eb) | 0x40; // set the exponent sign bit
}
this.A = 0; // required by specs
this.B = (sb*128 + eb)*0x8000000000 + mb; // Final Answer
}
}
this.X = xx; // for display purposes only
};
/**************************************/
B5500Processor.prototype.doublePrecisionAdd = function(adding) {
/* Adds the double-precision contents of the A and B registers to the double-
precision contents of the top two words in the memory stack, leaving the result
in A and B. If "adding" is not true, the sign of A is complemented to accomplish
subtraction instead of addition */
var carry = 0; // overflow carry flag
var d = 0; // shifting digit between registers
var ea; // signed exponent of A
var eb; // signed exponent of B
var ma; // absolute mantissa of A*8
var mb; // absolute mantissa of B*8
var sa; // mantissa sign of A (0=positive)
var sb; // mantissa sign of B (ditto)
var xa; // extended mantissa for A
var xb; // extended mantissa for B
// Estimate some general overhead and account for stack manipulation we don't do
this.cycleCount += B5500Processor.memCycles*4 + 8;
this.adjustABFull(); // extract the top (A) operand fields:
ma = this.A % 0x8000000000; // extract the A mantissa
xa = this.B % 0x8000000000; // extract the A mantissa extension
ea = (this.A - ma)/0x8000000000;
sa = ((ea >>> 7) & 0x01);
ea = (ea & 0x40 ? -(ea & 0x3F) : (ea & 0x3F));
this.AROF = this.BROF = 0; // empty the TOS registers
this.adjustABFull(); // extract the second (B) operand fields:
mb = this.A % 0x8000000000; // extract the B mantissa
xb = this.B % 0x8000000000; // extract the B mantissa extension
eb = (this.B - mb)/0x8000000000;
sb = (eb >>> 7) & 0x01;
eb = (eb & 0x40 ? -(eb & 0x3F) : (eb & 0x3F));
if (ma == 0 && xa == 0) { // if A is zero
if (mb == 0 && xb == 0) { // and B is zero
this.A = this.B = 0; // result is all zeroes
} else {
this.A %= 0x800000000000; // otherwise, result is B with flag bit reset
}
} else if (mb == 0 && xb == 0 && adding) { // otherwise, if B is zero and we're adding,
this.B = xa; // reconstruct A operand with flag bit reset
this.A = ((sa*2 + (ea < 0 ? 1 : 0))*64 + (ea < 0 ? -ea : ea))*0x8000000000 + ma;
} else { // so much for the simple cases...
// If the exponents are unequal, normalize the larger and scale the smaller
// until they are in alignment, or one of the mantissas becomes zero
if (ea > eb) {
// Normalize A for 78 bits (26 octades)
while (ma < 0x1000000000 && ea != eb) {
this.cycleCount++;
d = (xa - xa%0x1000000000)/0x1000000000;
ma = ma*8 + d; // shift left
xa = (xa % 0x1000000000)*8;
ea--;
}
// Scale B until its exponent matches or mantissa goes to zero
while (ea != eb) {
this.cycleCount++;
d = mb % 8;
mb = (mb - d)/8; // shift right into extension
xb = (xb - xb%8)/8 + d*0x1000000000;
if (mb && xb) {
eb++;
} else {
eb = ea; // if B=0, result will have exponent of A
}
}
} else if (ea < eb) {
// Normalize B for 78 bits (26 octades)
while (mb < 0x1000000000 && eb != ea) {
this.cycleCount++;
d = (xb - xb%0x1000000000)/0x1000000000;
mb = mb*8 + d; // shift left
xb = (xb % 0x1000000000)*8;
eb--;
}
// Scale A until its exponent matches or mantissa goes to zero
while (eb != ea) {
this.cycleCount++;
d = ma % 8;
ma = (ma - d)/8; // shift right into extension
xa = (xa - xa%8)/8 + d*0x1000000000;
if (ma && xa) {
ea++;
} else {
ea = eb; // if A=0, kill the scaling loop
}
}
}
// At this point, the exponents are aligned (or one of the mantissas
// is zero), so do the actual 78-bit addition as two 40-bit, signed, twos-
// complement halves. Note that computing the twos-complement of the
// extension requires a borrow from the high-order part, so the borrow
// is taken from the 40-bit twos-complement base (i.e., using 0xFFFFFFFFFF
// instead of 0x10000000000).
if (sb) { // if B negative, compute B 2s complement
this.cycleCount += 2;
xb = 0x8000000000 - xb;
mb = 0xFFFFFFFFFF - mb;
}
if (sa ^ (adding ? 0 : 1)) { // if A negative XOR subtracting, compute A 2s complement
this.cycleCount += 2;
xa = 0x8000000000 - xa;
ma = 0xFFFFFFFFFF - ma;
}
xb += xa; // add the extension parts
if (xb >= 0x8000000000) { // deal with carry out of extension part
mb++; // into high-order part
xb %= 0x8000000000;
}
mb += ma; // add the high-order parts
// Check for overflow: if the result occupies more than 40 bits, we know
// that overflow occurred; otherwise if both internal signs were positive
// and we have a twos-complement negative result, overflow occurred; otherwise
// if both internal signs were negative and we have a positive result,
// overflow occurred. Set the carry flag and adjust the result as necessary.
if (mb >= 0x10000000000) { // if result overflowed 40 bits
carry = 1; // set the carry flag
mb -= 0x8000000000; // and adjust result for the overflow
} else if (sb == (sa ^ (adding ? 0 : 1))) { // if the signs of the internal addition are the same
if (sb && mb < 0x8000000000) { // if signs were negative and result is positive
carry = 1; // overflow occurred: set carry flag
mb += 0x8000000000; // and adjust result for the overflow
} else if (!sb && mb >= 0x8000000000) { // if signs were positive and result is negative
carry = 1; // overflow occurred: set the carry flag
mb -= 0x8000000000; // and adjust result for the overflow
}
}
// Determine the resulting sign and decomplement as necessary
if (mb < 0x8000000000) {
sb = 0; // it's positive
} else {
sb = 1; // it's negative
this.cycleCount++;
xb = 0x8000000000 - xb;
mb = 0xFFFFFFFFFF - mb;
}
// Scale or normalize as necessary
if (carry) { // overflow occurred, so scale it in
this.cycleCount++;
d = mb % 8; // get the shift digit from high-order part
mb = (mb - d)/8 + 0x1000000000; // shift right and insert the overflow bit
xb = (xb - xb%8)/8 + d*0x1000000000; // shift the extension and insert the shift digit
eb++;
} else {
while (mb < 0x1000000000 && mb & xb) { // Normalize
this.cycleCount++;
d = (xb - xb%0x1000000000)/0x1000000000;// get the rounding digit from X
xb = (xb%0x1000000000)*8; // shift B and X left together
mb = mb*8 + d;
eb--;
}
}
if (mb == 0 && xb == 0) {
this.A = this.B = 0;
} else {
// Check for exponent over/underflow
if (eb > 63) {
eb %= 64;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xB0; // set I05/6/8: exponent-overflow
this.cc.signalInterrupt();
}
} else if (eb < -63) {
eb = ((-eb) % 64) | 0x40; // mod the exponent and set its sign
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xA0; // set I06/8: exponent-underflow
this.cc.signalInterrupt();
}
} else if (eb < 0) {
eb = (-eb) | 0x40; // set the exponent sign bit
}
this.X = xb; // for display purposes only
this.B = xb;
this.A = (sb*128 + eb)*0x8000000000 + mb; // Final Answer
}
}
};
/**************************************/
B5500Processor.prototype.computeRelativeAddr = function(offset, cEnabled) {
/* Computes an absolute memory address from the relative "offset" parameter
and leaves it in the M register. See Table 6-1 in the B5500 Reference
Manual. "cEnable" determines whether C-relative addressing is permitted.
This offset must be in (0..1023) */
if (this.SALF) {
switch (offset >>> 7) {
case 0:
case 1:
case 2:
case 3:
this.M = (this.R*64) + (offset & 0x1FF);
break;
case 4:
case 5:
if (this.MSFF) {
this.M = (this.R*64) + 7;
this.access(0x06); // M = [M].[18:15]
this.M += (offset & 0xFF);
} else {
this.M = this.F + (offset & 0xFF);
}
break;
case 6:
if (cEnabled) {
this.M = this.C + (offset & 0x7F);
} else {
this.M = (this.R*64) + (offset & 0x7F);
}
break;
case 7:
if (this.MSFF) {
this.M = (this.R*64) + 7;
this.access(0x06); // M = [M].[18:15]
this.M -= (offset & 0x7F);
} else {
this.M = this.F - (offset & 0x7F);
}
break;
} // switch
} else {
this.M = (this.R*64) + (offset & 0x3FF);
}
};
/**************************************/
B5500Processor.prototype.indexDescriptor = function() {
/* Indexes a descriptor and, if successful leaves the indexed value in
the A register. Returns 1 if an interrupt is set and the syllable is
to be exited */
var aw = this.A; // local copy of A reg
var bw; // local copy of B reg
var interrupted = 0; // fatal error, interrupt set
var xe; // index exponent
var xm; // index mantissa
var xo; // last index octade shifted off
var xs; // index mantissa sign
var xt; // index exponent sign
this.adjustBFull();
bw = this.B;
xm = (bw % 0x8000000000);
xe = (bw - xm)/8;
xs = (xe >>> 7) & 0x01;
xt = (xe >>> 6) & 0x01;
xe = (xt ? -(xe & 0x3F) : (xe & 0x3F));
// Normalize the index, if necessary
if (xe < 0) { // index exponent is negative
do {
this.cycleCount++;
xo = xm % 8;
xm = (xm - xo)/8;
} while (++xe < 0);
if (xo >= 4) {
xm++; // round the index
}
} else if (xe > 0) { // index exponent is positive
do {
this.cycleCount++;
if (xm < 0x1000000000) {
xm *= 8;
} else { // oops... integer overflow normalizing the index
xe = 0; // kill the loop
interrupted = 1;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0xC0; // set I07/8: int-overflow
this.cc.signalInterrupt();
}
}
} while (--xe > 0);
}
// Now we have an integerized index value in xm
if (!interrupted) {
if (xs) { // oops... negative index
interrupted = 1;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0x90; // set I05/8: invalid-index
this.cc.signalInterrupt();
}
} else if (xm >= this.cc.fieldIsolate(aw, 8, 10)) {
interrupted = 1; // oops... index out of bounds
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0x90; // set I05/8: invalid-index
this.cc.signalInterrupt();
}
} else { // we finally have a valid index
this.A = this.cc.fieldInsert(aw, 33, 15, aw % 0x8000 + xm % 0x400);
this.BROF = 0;
}
}
return interrupted;
};
/**************************************/
B5500Processor.prototype.presenceTest = function(word) {
/* Tests and returns the presence bit [2:1] of the "word" parameter. If
0, the p-bit interrupt is set; otherwise no further action */
if (word % 0x400000000000 >= 0x200000000000) {
return 1;
} else {
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0x70; // set I05/6/7: p-bit
this.cc.signalInterrupt();
}
return 0;
}
};
/**************************************/
B5500Processor.prototype.buildMSCW = function() {
/* Return a Mark Stack Control Word from current processor state */
return this.F * 0x8000 +
this.SALF * 0x40000000 +
this.MSFF * 0x80000000 +
this.R * 0x200000000 +
0xC00000000000;
};
/**************************************/
B5500Processor.prototype.applyMSCW = function(word) {
/* Set processor state from fields of the Mark Stack Control
Word in the "word" parameter */
var f;
f = word % 0x8000; // [33:15], not used
word = (word-f)/0x8000;
this.F = f = word % 0x8000; // [18:15], F register
word = (word-f)/0x8000;
this.SALF = f = word % 2; // [17:1], SALF
word = (word-f)/2;
this.MSFF = word % 2; // [16:1], MSFF
word = (word - word%4)/4;
this.R = word % 0x200; // [6:9], R
};
/**************************************/
B5500Processor.prototype.buildRCW = function(descriptorCall) {
/* Return a Return Control Word from the current processor state */
return this.C +
this.F * 0x8000 +
this.K * 0x40000000 +
this.G * 0x200000000 +
this.L * 0x1000000000 +
this.V * 0x4000000000 +
this.H * 0x20000000000 +
(descriptorCall ? 0xE00000000000 : 0xC00000000000);
};
/**************************************/
B5500Processor.prototype.applyRCW = function(word, inline) {
/* Set processor state from fields of the Return Control Word in
the "word" parameter. If "inline" is truthy, C & L are NOT restored from
the RCW. Returns the state of the OPDC/DESC bit [2:1] */
var f;
f = word % 0x8000; // [33:15], C
if (!inline) {
this.C = f;
this.access(0x30); // P = [C], fetch new program word
}
word = (word-f)/0x8000;
this.F = f = word % 0x8000; // [18:15], F
word = (word-f)/0x8000;
this.K = f = word % 8; // [15:3], K
word = (word-f)/8;
this.G = f = word % 8; // [12:3], G
word = (word-f)/8;
f = word % 4; // [10:2], L
if (!inline) {
this.L = f;
}
word = (word-f)/4;
this.V = f = word % 8; // [7:3], V
word = (word-f)/8;
this.H = word % 8; // [4:3], H
word = (word - word % 0x10)/0x10;
return word % 2; // [2:1], DESC bit
};
/**************************************/
B5500Processor.prototype.enterCharModeInline = function() {
/* Implements the 4441=CMN syllable */
var bw; // local copy of B reg
this.adjustAEmpty(); // flush TOS registers, but tank TOS value in A
if (this.BROF) {
this.A = this.B; // tank the DI address in A
this.adjustBEmpty();
} else {
this.access(0x02) // A = [S]: tank the DI address
}
this.B = this.buildRCW(0);
this.adjustBEmpty();
this.MSFF = 0;
this.SALF = 1;
this.F = this.S;
this.R = 0;
this.CWMF = 1;
this.X = this.S * 0x8000; // inserting S into X.[18:15], but X is zero at this point
this.S = 0;
this.B = bw = this.A;
this.BROF = 1;
this.AROF = 0;
this.V = this.K = 0;
// execute the portion of CM XX04=RDA operator starting at J=2
if (bw < 0x800000000000) { // B contains an operand
this.S = bw % 0x8000;
this.K = (bw % 0x40000) >>> 15;
} else { // B contains a descriptor
if (bw % 0x400000000000 < 0x200000000000) { // it's an absent descriptor
if (this.NCSF) {
// NOTE: docs do not mention if this is inhibited in control state, but we assume it is
this.I = (this.I & 0x0F) | 0x70; // set I05/6/7: P-bit
this.cc.signalInterrupt();
}
} else {
this.S = bw % 0x8000;
}
}
};
/**************************************/
B5500Processor.prototype.enterSubroutine = function(descriptorCall) {
/* Enters a subroutine via the present program descriptor in A as part
of an OPDC or DESC syllable. Also handles accidental entry */
var aw = this.A; // local copy of word in A reg
var bw; // local copy of word in B reg
var arg = this.cc.bit(aw, 5); // descriptor argument bit
var mode = this.cc.bit(aw, 4); // descriptor mode bit (1-char mode)
if (arg && !this.MSFF) {
; // just leave the PD on TOS
} else if (mode && !arg) {
; // ditto
} else {
// Now we are really going to enter the subroutine
this.adjustBEmpty();
if (!arg) {
// Accidental entry -- mark the stack
this.B = this.buildMSCW();
this.adjustBEmpty();
}
// Push a RCW
this.B = this.buildRCW(descriptorCall);
this.adjustBEmpty();
// Fetch the first word of subroutine code
this.C = aw % 0x8000;
this.L = 0;
this.access(0x30);
// Fix up the rest of the registers
if (arg) {
this.F = this.S;
} else {
this.F = this.cc.fieldIsolate(aw, 18, 15);
}
this.AROF = 0;
this.BROF = 0;
this.SALF = 1;
this.MSFF = 0;
if (mode) {
this.CWMF = 1;
this.R = 0;
this.X = this.cc.fieldInsert(this.X, 18, 15, this.S);
this.S = 0;
}
}
};
/**************************************/
B5500Processor.prototype.exitSubroutine = function(inline) {
/* Exits a subroutine by restoring the processor state from RCW and MSCW words
in the stack. "inline" indicates the C & L registers are NOT restored from the
RCW. The RCW is assumed to be in the B register, pointing to the MSCW.
The A register is not affected by this routine. If SALF & MSFF bits in the MSCW
are set, link back through the MSCWs until one is found that has either bit not
set, and store that MSCW at [R]+7. This is the last prior MSCW that actually
points to a RCW, thus skipping over any pending subroutine calls that are still
building their parameters in the stack. Returns results as follows:
0 = entered by OPDC
1 = entered by DESC
2 = flag bit interrupt set, terminate operator
*/
var result;
if (this.B < 0x800000000000) { // flag bit not set
result = 2;
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0x80; // set I08: flag-bit
this.cc.signalInterrupt();
}
} else { // flag bit is set
result = this.applyRCW(this.B, inline);
this.X = this.B % 0x8000000000; // save F setting from MSCW to restore S at end
this.S = this.F;
this.access(0x03); // B = [S], fetch the MSCW
this.applyMSCW(this.B);
if (this.MSFF && this.SALF) {
this.Q |= 0x20; // set Q06F, not used except for display
do {
this.S = (this.B % 0x40000000) >>> 15;
this.access(0x03); // B = [S], fetch prior MSCW
} while (((this.B - this.B % 0x40000000)/0x40000000) % 4 == 3); // MSFF & SALF
this.S = (this.R*64) + 7;
this.access(0x0B); // [S] = B, store last MSCW at [R]+7
}
this.S = ((this.X % 0x40000000) >>> 15) - 1;
this.BROF = 0;
}
return result;
};
/**************************************/
B5500Processor.prototype.operandCall = function() {
/* OPDC, the moral equivalent of "load accumulator" on lesser
machines. Assumes the syllable has already loaded a word into A.
See Figures 6-1, 6-3, and 6-4 in the B5500 Reference Manual */
var aw; // local copy of A reg value
var interrupted = 0; // interrupt occurred
aw = this.A;
if (aw >= 0x800000000000) {
// It's not a simple operand
switch (this.cc.fieldIsolate(aw, 1, 3)) {
case 2:
case 3:
// Present data descriptor
if (this.cc.fieldIsolate(aw, 8, 10)) {
interrupted = this.indexDescriptor();
// else descriptor is already indexed (word count 0)
}
if (!interrupted) {
this.M = this.A % 0x8000;
this.access(0x04); // A = [M]
if (this.A >= 0x800000000000 && this.NCSF) {
// Flag bit is set
this.I = (this.I & 0x0F) | 0x80; // set I08: flag-bit interrupt
this.cc.signalInterrupt();
}
}
break;
case 7:
// Present program descriptor
this.enterSubroutine(0);
break;
case 0:
case 1:
case 5:
// Absent data or program descriptor
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0x70; // set I05/6/7: P-bit
this.cc.signalInterrupt();
// else if control state, we're done
}
break;
default:
// Miscellaneous control word -- leave as is
break;
}
}
// Reset variant-mode R-relative addressing, if enabled
if (this.VARF && !interrupted) {
this.SALF = 1;
this.VARF = 0;
}
};
/**************************************/
B5500Processor.prototype.descriptorCall = function() {
/* DESC, the moral equivalent of "load address" on lesser machines.
Assumes the syllable has already loaded a word into A, and that the
address of that word is in M.
See Figures 6-2, 6-3, and 6-4 in the B5500 Reference Manual */
var aw = this.A; // local copy of A reg value
var interrupted = 0; // interrupt occurred
if (aw < 0x800000000000) {
// It's a simple operand
this.A = this.M + 0xA00000000000;
} else {
// It's not a simple operand
switch (this.cc.fieldIsolate(aw, 1, 3)) {
case 2:
case 3:
// Present data descriptor
if (this.cc.fieldIsolate(aw, 8, 10)) {
interrupted = this.indexDescriptor();
this.A = this.cc.fieldInsert(this.A, 8, 10, 0); // set word count to zero
// else descriptor is already indexed (word count 0)
}
break;
case 7:
// Present program descriptor
this.enterSubroutine(1);
break;
case 0:
case 1:
case 5:
// Absent data or program descriptor
if (this.NCSF) {
this.I = (this.I & 0x0F) | 0x70; // set I05/6/7: p-bit
this.cc.signalInterrupt();
// else if control state, we're done
}
break;
default:
// Miscellaneous control word
this.A = this.M + 0xA00000000000;
break;
}
}
// Reset variant-mode R-relative addressing, if enabled
if (this.VARF && !interrupted) {
this.SALF = 1;
this.VARF = 0;
}
};
/**************************************/
B5500Processor.prototype.run = function() {
/* Instruction execution driver for the B5500 processor. This function is
an artifact of the emulator design and does not represent any physical
process or state of the processor. This routine assumes the registers are
set up -- in particular there must be a syllable in T with TROF set, the
current program word must be in P with PROF set, and the C & L registers
must point to the next syllable to be executed.
This routine will run until cycleCount >= cycleLimit or !this.busy */
var noSECL = 0; // to support char mode dynamic count from CRF syllable
var opcode; // copy of T register
var t1; // scratch variable for internal instruction use
var t2; // ditto
var t3; // ditto
var t4; // ditto
var variant; // high-order six bits of T register
do {
this.Q = 0;
this.Y = 0;
this.Z = 0;
opcode = this.T;
if (this.CWMF) {
/***********************************************************
* Character Mode Syllables *
***********************************************************/
variant = opcode >>> 6;
do { // inner loop to support CRF dynamic repeat count
noSECL = 0; // force off by default (set by CRF)
switch (opcode & 0x3F) {
case 0x00: // XX00: CMX, EXC: Exit character mode
this.adjustBEmpty(); // store destination string
this.S = this.F;
this.access(0x03); // B = [S], fetch the RCW
this.exitSubroutine(variant & 0x01);// exit vs. exit inline
this.AROF = this.BROF = 0;
this.X = this.M = this.N = 0;
this.CWMF = 0;
break;
case 0x02: // XX02: BSD=Skip bit destination
this.cycleCount += variant;
t1 = this.K*6 + this.V + variant;
while (t1 >= 48) {
if (this.BROF) { // skipped off initial word, so
this.access(0x0B); // [S] = B
this.BROF = 0; // invalidate B
}
this.S++;
t1 -= 48;
}
this.K = (t1 - (this.V = t1 % 6))/6;
break;
case 0x03: // XX03: BSS=Skip bit source
this.cycleCount += variant;
t1 = this.G*6 + this.H + variant;
while (t1 >= 48) {
this.M++; // skipped off initial word, so
this.AROF = 0; // invalidate A
t1 -= 48;
}
this.G = (t1 - (this.H = t1 % 6))/6;
break;
case 0x04: // XX04: RDA=Recall destination address
this.cycleCount += variant;
if (this.BROF) {
this.access(0x0B); // [S] = B
this.BROF = 0;
}
this.S = this.F - variant;
this.access(0x03); // B = [S]
this.S = this.B % 0x8000;
this.V = 0;
if (this.B >= 0x800000000000) { // if it's a descriptor,
this.K = 0; // force K to zero and
this.presenceTest(this.B); // just take the side effect of any p-bit interrupt
} else {
this.K = this.cc.fieldIsolate(this.B, 18, 3);
}
break;
case 0x05: // XX05: TRW=Transfer words
if (this.BROF) {
this.access(0x0B); // [S] = B
this.BROF = 0;
}
if (this.G || this.H) {
this.G = this.H = 0;
this.M++;
this.AROF = 0;
}
if (this.K || this.V) {
this.K = this.V = 0;
this.S++;
}
if (variant) { // count > 0
if (!this.AROF) {
this.access(0x04); // A = [M]
}
do {
this.access(0x0A); // [S] = A
this.S++;
this.M++;
this.access(0x04); // A = [M]
} while (--variant);
}
break;
case 0x06: // XX06: SED=Set destination address
this.cycleCount += variant;
if (this.BROF) {
this.access(0x0B); // [S] = B
this.BROF = 0;
}
this.S = this.F - variant;
this.K = this.V = 0;
break;
case 0x07: // XX07: TDA=Transfer destination address
this.cycleCount += 6;
this.streamAdjustDestChar();
if (this.BROF) {
this.access(0x0B); // [S] = B, store B at dest addresss
}
t1 = this.M; // save M (not the way the hardware did it)
t2 = this.G; // save G (ditto)
this.M = this.S; // copy dest address to source address
this.G = this.K;
this.A = this.B; // save B
this.AROF = this.BROF;
if (!this.AROF) {
this.access(0x04); // A = [M], load A from source address
}
for (variant=3; variant>0; variant--) {
this.B = (this.B % 0x100000000000000)*0x40 + (this.Y = this.cc.fieldIsolate(this.A, this.G*6, 6));
if (this.G < 7) {
this.G++;
} else {
this.G = 0;
this.M++;
this.access(0x04); // A = [M]
}
}
this.S = this.B % 0x8000;
this.K = this.fieldIsolate(this.B, 18, 3);
this.M = t1; // restore M & G
this.G = t2;
this.AROF = this.BROF = 0; // invalidate A & B
break;
case 0x09: // XX11: control state ops
switch (variant) {
case 0x14: // 2411: ZPI=Conditional Halt
// TODO: this needs to test for the STOP OPERATOR switch
// TODO: on the maintenance panel otherwise it is a NOP.
break;
case 0x18: // 3011: SFI=Store for Interrupt
this.storeForInterrupt(0);
break;
case 0x1C: // 3411: SFT=Store for Test
this.storeForInterrupt(1);
break;
default: // Anything else is a no-op
break;
} // end switch for XX11 ops
case 0x0A: // XX12: TBN=Transfer blank for numeric
this.MSFF = 1; // initialize true-false FF
this.streamToDest(variant, function(bb, count) {
var c = this.Z = this.cc.fieldIsolate(this.B, bb, 6);
var result = 0;
if (c > 0 && c <= 9) {
this.MSFF = 0; // numeric, non-zero: stop blanking
this.Q |= 0x04; // set Q03F (display only)
result = 1; // terminate, pointing at this char
} else {
this.B = this.cc.fieldInsert(this.B, bb, 6, 0x30); // replace with blank
}
return result;
});
break;
case 0x0C: // XX14: SDA=Store destination address
this.cycleCount += variant;
this.streamAdjustDestChar();
this.A = this.B; // save B
this.AROF = this.BROF;
this.B = this.K*0x8000 * this.S;
t1 = this.S; // save S (not the way the hardware did it)
this.S -= variant;
this.access(0x0B); // [S] = B
this.S = t1; // restore S
this.B = this.A; // restore B from A
this.BROF = this.AROF;
this.AROF = 0; // invalidate A
break;
case 0x0D: // XX15: SSA=Store source address
this.cycleCount += variant;
this.streamAdjustSourceChar();
this.A = this.B; // save B
this.AROF = this.BROF;
this.B = this.G*0x8000 * this.M;
t1 = this.M; // save M (not the way the hardware did it)
this.M -= variant;
this.access(0x0D); // [M] = B
this.M = t1; // restore M
this.B = this.A; // restore B from A
this.BROF = this.AROF;
this.AROF = 0; // invalidate A
break;
case 0x0E: // XX16: SFD=Skip forward destination
this.cycleCount += (variant >>> 3) + (variant & 0x07);
this.streamAdjustDestChar();
if (this.BROF && this.K + variant >= 8) {
this.access(0x0B); // will skip off the current word,
this.BROF = 0; // so store and invalidate B
}
t1 = this.S*8 + this.K - variant;
this.S = t1 >>> 3;
this.K = t1 & 0x07;
break;
case 0x0F: // XX17: SRD=Skip reverse destination
this.cycleCount += (variant >>> 3) + (variant & 0x07);
this.streamAdjustDestChar();
if (this.BROF && this.K < variant) {
this.access(0x0B); // will skip off the current word,
this.BROF = 0; // so store and invalidate B
}
t1 = this.S*8 + this.K - variant;
this.S = t1 >>> 3;
this.K = t1 & 0x07;
break;
break;
case 0x12: // XX22: SES=Set source address
this.cycleCount += variant;
this.M = this.F - variant;
this.G = this.H = 0;
this.AROF = 0;
break;
case 0x14: // XX24: TEQ=Test for equal
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = this.cc.fieldIsolate(this.A, this.G*6, 6);
this.MSFF = (t1 == variant ? 1 : 0);
break;
case 0x15: // XX25: TNE=Test for not equal
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = this.cc.fieldIsolate(this.A, this.G*6, 6);
this.MSFF = (t1 != variant ? 1 : 0);
break;
case 0x16: // XX26: TEG=Test for equal or greater
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = B5500Processor.collate[this.cc.fieldIsolate(this.A, this.G*6, 6)];
t2 = B5500Processor.collate[variant];
this.MSFF = (t1 >= t2 ? 1 : 0);
break;
case 0x17: // XX27: TGR=Test for greater
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = B5500Processor.collate[this.cc.fieldIsolate(this.A, this.G*6, 6)];
t2 = B5500Processor.collate[variant];
this.MSFF = (t1 > t2 ? 1 : 0);
break;
case 0x18: // XX30: SRS=Skip reverse source
this.cycleCount += (variant >>> 3) + (variant & 0x07);
this.streamAdjustSourceChar();
if (this.G < variant) {
this.AROF = 0; // will skip off the current word
}
t1 = this.M*8 + this.G - variant;
this.M = t1 >>> 3;
this.G = t1 & 0x07;
break;
case 0x19: // XX31: SFS=Skip forward source
this.cycleCount += (variant >>> 3) + (variant & 0x07);
this.streamAdjustSourceChar();
if (this.G + variant >= 8) { // will skip off the current word
this.AROF = 0;
}
t1 = this.M*8 + this.G + variant;
this.G = t1 & 0x07;
this.M = t1 >>> 3;
break;
case 0x1A: // XX32: ---=Field subtract (aux) !! ??
this.fieldArithmetic(variant, false);
break;
case 0x1B: // XX33: ---=Field add (aux) !! ??
this.fieldArithmetic(variant, true);
break;
case 0x1C: // XX34: TEL=Test for equal or less
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = B5500Processor.collate[this.cc.fieldIsolate(this.A, this.G*6, 6)];
t2 = B5500Processor.collate[variant];
this.MSFF = (t1 <= t2 ? 1 : 0);
break;
case 0x1D: // XX35: TLS=Test for less
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = B5500Processor.collate[this.cc.fieldIsolate(this.A, this.G*6, 6)];
t2 = B5500Processor.collate[variant];
this.MSFF = (t1 < t2 ? 1 : 0);
break;
case 0x1E: // XX36: TAN=Test for alphanumeric
this.streamAdjustSourceChar();
if (!this.AROF) {
this.access(0x04); // A = [M]
}
this.Y = t1 = this.cc.fieldIsolate(this.A, this.G*6, 6);
this.Z = variant; // for display only
if (B5500Processor.collate[t1] > B5500Processor.collate[variant]) { // alphanumeric unless | or !
this.MSFF = (t1 == 0x20 ? 0 : (t1 == 0x3C ? 0 : 1));
} else { // alphanumeric if equal
this.Q |= 0x04; // set Q03F (display only)
this.MSFF = (t1 == variant ? 1 : 0);
}
break;
case 0x1F: // XX37: BIT=Test bit
if (!this.AROF) {
this.access(0x04); // A = [M]
}
t1 = (this.Y = this.cc.fieldIsolate(this.A, this.G*6, 6)) >>> 5-this.H;
this.MSFF = ((t1 & 0x01) == (variant & 0x01) ? 1 : 0);
break;
case 0x20: // XX40: INC=Increase TALLY
if (variant) {
this.R = (this.R + variant) & 0x3F;
// else it's a character-mode no-op
}
break;
case 0x21: // XX41: STC=Store TALLY
this.cycleCount += variant;
this.A = this.B; // save B
this.AROF = 0; // invalidate A
this.B = this.F; // save RCW address in B (why??)
if (this.BROF) {
this.access(0x0A); // [S] = A, save original B contents
this.BROF = 0;
}
this.A = this.B; // move saved F address to A (why??)
this.B = this.R; // copy the TALLY value to B
t1 = this.S; // save S (not the way the hardware did it)
this.S = this.F - variant;
this.access(0x0B); // [S] = B, store the TALLY value
this.B = this.A; // restore F address from A (why??)
this.S = t1; // restore S
this.BROF = 0; // invalidate B
break;
case 0x22: // XX42: SEC=Set TALLY
this.R = variant;
break;
case 0x23: // XX43: CRF=Call repeat field
this.cycleCount += variant;
this.A = this.B; // save B in A
this.AROF = this.BROF;
t1 = this.S; // save S (not the way the hardware did it)
this.S = this.F - variant; // compute parameter address
this.access(0x03); // B = [S]
variant = this.B % 0x40; // dynamic repeat count is low-order 6 bits
this.S = t1; // restore S
this.B = this.A; // restore B from A
this.BROF = this.AROF;
this.AROF = 0; // invalidate A
noSECL = 1; // >>> override normal instruction fetch <<<
opcode = this.cc.fieldIsolate(this.P, this.L*12, 12);
if (variant) { // if repeat count from parameter > 0
this.T = opcode & 0x3F + variant*0x40; // apply it to the next syl
} else { // otherwise construct JFW (XX47) using
this.T = (opcode & 0xFC0) + 0x27; // repeat count from next syl (whew!)
}
break;
case 0x24: // XX44: JNC=Jump out of loop conditional
if (!this.MSFF) {
this.jumpOutOfLoop(variant);
}
break;
case 0x25: // XX45: JFC=Jump forward conditional
if (!this.MSFF) { // conditional on TFFF
this.cycleCount += (variant >>> 2) + (variant & 0x03);
this.jump(variant, false);
}
break;
case 0x26: // XX46: JNS=Jump out of loop
this.jumpOutOfLoop(variant);
break;
case 0x27: // XX47: JFW=Jump forward unconditional
this.cycleCount += (variant >>> 2) + (variant & 0x03);
this.jump(variant, false);
break;
case 0x28: // XX50: RCA=Recall control address
this.cycleCount += variant;
this.A = this.B; // save B in A
this.AROF = this.BROF;
t1 = this.S; // save S (not the way the hardware did it)
this.S = this.F - variant;
this.access(0x03); // B = [S]
this.S = t1;
this.C = this.B % 0x8000;
if (this.B >= 0x800000000000) { // if it's a descriptor,
this.L = 0; // force L to zero and
if (this.presenceTest(this.B)) {// if present, initiate a fetch to P
this.access(0x30); // P = [C]
}
} else {
t1 = this.cc.fieldIsolate(this.B, 10, 2);
if (t1 < 3) { // if not a descriptor, increment the address
this.L = t1+1;
} else {
this.L = 0;
this.C++;
}
this.access(0x30); // P = [C]
}
this.B = this.A; // restore B
this.BROF = this.AROF
this.AROF = 0; // invalidate A
break;
case 0x29: // XX51: ENS=End loop
this.cycleCount += 4;
this.A = this.B; // save B in A
this.AROF = this.BROF;
t1 = this.X;
variant = this.cc.fieldIsolate(t1, 12, 6); // get repeat count
if (variant) { // loop count exhausted?
this.C = this.cc.fieldIsolate(t1, 33, 15); // no, restore C, L, and P to loop again
this.L = this.cc.fieldIsolate(t1, 10, 2);
this.access(0x30); // P = [C]
this.X = this.cc.fieldInsert(t1, 12, 6, variant-1); // store decremented count in X
} else {
t2 = this.S; // save S (not the way the hardware did it)
this.S = this.cc.fieldIsolate(t1, 18, 15); // get prior LCW addr from X value
this.access(0x03); // B = [S], fetch prior LCW from stack
this.S = t2; // restore S
this.X = this.cc.fieldIsolate(this.B, 9, 39); // store prior LCW (less control bits) in X
}
this.B = this.A; // restore B
this.BROF = this.AROF
this.AROF = 0; // invalidate A
break;
case 0x2A: // XX52: BNS=Begin loop
this.cycleCount += 4;
this.A = this.B; // save B in A (note that BROF is not altered)
t1 = this.cc.fieldInsert( // construct new LCW: insert repeat count
this.cc.fieldInsert( // insert L
this.cc.fieldInsert(this.X, 33, 15, this.C), // insert C
10, 2, this.L),
12, 6, (variant ? variant-1 : 0)); // decrement count for first iteration
this.B = this.cc.fieldInsert(this.X, 0, 2, 3); // set control bits [0:2]=3
t2 = this.S; // save S (not the way the hardware did it)
this.S = this.cc.fieldIsolate(t1, 18, 15)+1; // get F value from X value and ++
this.access(0x0B); // [S] = B, save prior LCW in stack
this.X = this.cc.fieldInsert(t1, 18, 15, this.S); // update F value in X
this.S = t2; // restore S
this.B = this.A; // restore B (note that BROF is still relevant)
this.AROF = 0; // invalidate A
break;
case 0x2B: // XX53: RSA=Recall source address
this.cycleCount += variant;
this.A = this.B; // save B
this.AROF = this.BROF;
this.M = this.F - variant;
this.access(0x05); // B = [M]
this.M = this.B % 0x8000;
this.H = 0;
if (this.B >= 0x800000000000) { // if it's a descriptor,
this.G = 0; // force G to zero and
this.presenceTest(this.B); // just take the side effect of any p-bit interrupt
} else {
this.G = this.cc.fieldIsolate(this.B, 18, 3);
}
this.B = this.A; // restore B from A
this.BROF = this.AROF;
this.AROF = 0; // invalidate A
break;
case 0x2C: // XX54: SCA=Store control address
this.cycleCount += variant;
this.A = this.B; // save B
this.AROF = this.BROF;
t2 = this.S; // save S (not the way the hardware did it)
this.S = this.F - variant; // compute store address
this.B = this.fieldInsert( // construct control address: reset flag bit
this.cc.fieldInsert( // insert F (as saved in t2)
this.cc.fieldInsert( // insert L
this.cc.fieldInsert(this.B, 33, 15, this.C), // insert C
10, 2, this.L),
18, 15, t2),
0, 1, 0);
this.access(0x0B); // [S] = B
this.S = t2; // restore S
this.B = this.A; // restore B from A
this.BROF = this.AROF;
this.AROF = 0; // invalidate A
break;
case 0x2D: // XX55: JRC=Jump reverse conditional
if (!this.MSFF) { // conditional on TFFF
this.cycleCount += (variant >>> 2) + (variant & 0x03);
this.jump(-variant, false);
}
break;
case 0x2E: // XX56: TSA=Transfer source address
this.streamAdjustSourceChar();
if (this.BROF) {
this.access(0x0B); // [S] = B, store B at dest addresss
this.BROF = 0;
}
if (!this.AROF) {
this.access(0x04); // A = [M], load A from source address
}
for (variant=3; variant>0; variant--) {
this.B = (this.B % 0x100000000000000)*0x40 + (this.Y = this.cc.fieldIsolate(this.A, this.G*6, 6));
if (this.G < 7) {
this.G++;
} else {
this.G = 0;
this.M++;
this.access(0x04); // A = [M]
}
}
this.M = this.B % 0x8000;
this.G = this.fieldIsolate(this.B, 18, 3);
break;
case 0x2F: // XX57: JRV=Jump reverse unconditional
this.cycleCount += (variant >>> 2) + (variant & 0x03);
this.jump(-variant, false);
break;
case 0x30: // XX60: CEQ=Compare equal
this.compareSourceWithDest(variant);
this.MSFF = (this.Q & 0x04 ? 0 : 1); // if !Q03F, S=D
break;
case 0x31: // XX61: CNE=Compare not equal
this.compareSourceWithDest(variant);
this.MSFF = (this.Q & 0x04 ? 1 : 0); // if Q03F, S!=D
break;
case 0x32: // XX62: CEG=Compare greater or equal
this.compareSourceWithDest(variant);
this.MSFF = (this.Q & 0x04 ? this.MSFF : 1); // if Q03F&MSFF, S>D; if !Q03F, S=D
break;
case 0x33: // XX63: CGR=Compare greater
this.compareSourceWithDest(variant);
this.MSFF = (this.Q & 0x04 ? this.MSFF : 0); // if Q03F&MSFF, S>D
break;
case 0x34: // XX64: BIS=Set bit
this.streamBitsToDest(variant, 0xFFFFFFFFFFFF);
break;
case 0x35: // XX65: BIR=Reset bit
this.streamBitsToDest(variant, 0);
break;
case 0x36: // XX66: OCV=Output convert
this.streamOutputConvert(variant);
break;
case 0x37: // XX67: ICV=Input convert
this.streamInputConvert(variant);
break;
case 0x38: // XX70: CEL=Compare equal or less
this.compareSourceWithDest(variant);
this.MSFF = (this.Q & 0x04 ? 1-this.MSFF : 1); // if Q03F&!MSFF, S<D; if !Q03F, S=D
break;
case 0x39: // XX71: CLS=Compare less
this.compareSourceWithDest(variant);
this.MSFF = (this.Q & 0x04 ? 1-this.MSFF : 0); // if Q03F&!MSFF, S<D
break;
case 0x3A: // XX72: FSU=Field subtract
this.fieldArithmetic(variant, false);
break;
case 0x3B: // XX73: FAD=Field add
this.fieldArithmetic(variant, true);
break;
case 0x3C: // XX74: TRP=Transfer program characters
this.streamAdjustDestChar();
if (variant) { // count > 0
if (!this.BROF) {
this.access(0x03); // B = [S]
}
this.cycleCount += variant; // approximate the timing
t1 = (this.L*2 + variant & 0x01)*6; // P-reg bit number
t2 = this.K*6; // B-reg bit number
do {
this.Y = this.cc.fieldIsolate(this.P, t1, 6);
this.B = this.cc.fieldInsert(this.B, t2, 6, this.Y)
if (t2 < 42) {
t2 += 6;
this.K++;
} else {
t2 = 0;
this.K = 0;
this.access(0x0B); // [S] = B
this.S++;
if (variant < 8) { // just a partial word left
this.access(0x03); // B = [S]
}
}
if (t1 < 42) {
t1 += 6;
if (!(variant & 0x01)) {
this.L++;
}
} else {
t1 = 0;
this.L = 0;
this.C++;
this.access(0x30); // P = [C]
}
} while (--variant);
}
break;
case 0x3D: // XX75: TRN=Transfer source numerics
this.MSFF = 0; // initialize true-false FF
this.streamSourceToDest(variant, function(bb, count) {
var c = this.Y;
if (count == 1 && (c & 0x30) == 0x20) {
this.MSFF = 1; // neg. sign
}
this.B = this.cc.fieldInsert(this.B, bb, 6, c & 0x0F);
});
break;
case 0x3E: // XX76: TRZ=Transfer source zones
this.streamSourceToDest(variant, function(bb, count) {
this.B = this.cc.fieldInsert(this.B, bb, 2, this.Y);
});
break;
case 0x3F: // XX77: TRS=Transfer source characters
this.streamSourceToDest(variant, function(bb, count) {
this.B = this.cc.fieldInsert(this.B, bb, 6, this.Y);
});
break;
default: // everything else is a no-op
break;
} // end switch for character mode operators
} while (noSECL);
} else {
/***********************************************************
* Word Mode Syllables *
***********************************************************/
this.M = 0;
this.N = 0;
this.X = 0;
switch (opcode & 0x03) {
case 0: // LITC: Literal Call
this.adjustAEmpty();
this.A = opcode >>> 2;
this.AROF = 1;
break;
case 2: // OPDC: Operand Call
this.adjustAEmpty();
computeRelativeAddr(opcode >>> 2, 1);
this.access(0x04); // A = [M]
this.operandCall();
break;
case 3: // DESC: Descriptor (name) Call
this.adjustAEmpty();
computeRelativeAddr(opcode >>> 2, 1);
this.access(0x04); // A = [M]
this.descriptorCall();
break;
case 1: // all other word-mode operators
variant = opcode >>> 6;
switch (opcode & 0x3F) {
case 0x01: // XX01: single-precision numerics
switch (variant) {
case 0x01: // 0101: ADD=single-precision add
this.singlePrecisionAdd(true);
break;
case 0x03: // 0301: SUB=single-precision subtract
this.singlePrecisionAdd(false);
break;
case 0x04: // 0401: MUL=single-precision multiply
this.singlePrecisionMultiply();
break;
case 0x08: // 1001: DIV=single-precision floating divide
this.singlePrecisionDivide();
break;
case 0x18: // 3001: IDV=integer divide
this.integerDivide();
break;
case 0x38: // 7001: RDV=remainder divide
this.remainderDivide();
break;
}
break;
case 0x05: // XX05: double-precision numerics
switch (variant) {
case 0x01: // 0105: DLA=double-precision add
this.doublePrecisionAdd(true);
break;
case 0x03: // 0305: DLS=double-precision subtract
this.doublePrecisionAdd(false);
break;
case 0x04: // 0405: DLM=double-precision multiply
this.adjustABFull(); // FOR NOW, just do SP multiply
this.BROF = 0; // wipe out the first mantissa extension
this.adjustBFull(); // get second mantissa
this.S--; // wipe out the second mantissa extension
this.singlePrecisionMultiply();
this.A = this.B; // move high-order result to A
this.AROF = 1;
this.B = 0; // set low-order result to 0 in B
break;
case 0x08: // 1005: DLD=double-precision floating divide
this.adjustABFull(); // FOR NOW, just do SP divide
this.BROF = 0; // wipe out the first mantissa extension
this.adjustBFull(); // get second mantissa
this.S--; // wipe out the second mantissa extension
this.singlePrecisionDivide();
this.A = this.B; // move high-order result to A
this.AROF = 1;
this.B = 0; // set low-order result to 0 in B
break;
}
break;
case 0x09: // XX11: control state and communication ops
switch (variant) {
case 0x01: // 0111: PRL=Program Release
break;
case 0x02: // 0211: ITI=Interrogate Interrupt
if (this.cc.IAR && !this.NCSF) { // control-state only
this.C = this.cc.IAR;
this.L = 0;
this.S = 0x40; // stack address @100
this.cc.clearInterrupt();
this.cc.access(0x30); // P = [C]
}
break;
case 0x04: // 0411: RTR=Read Timer
if (!this.NCSF) { // control-state only
this.adjustAEmpty();
this.A = this.cc.CCI03F*64 + this.cc.TM;
}
break;
case 0x10: // 1011: COM=Communicate
if (this.NCSF) { // no-op in control state
this.M = (this.R*64) + 0x09; // address = R+@11
if (this.AROF) {
this.access(0x0C); // [M] = A
this.AROF = 0;
} else {
this.adjustBFull();
this.access(0x0D); // [M] = B
this.BROF = 0;
}
this.I = (this.I & 0x0F) | 0x40; // set I07
this.cc.signalInterrupt();
}
break;
case 0x11: // 2111: IOR=I/O Release
break;
case 0x12: // 2211: HP2=Halt Processor 2
if (!this.NCSF) { // control-state only
this.cc.haltP2();
}
break;
case 0x14: // 2411: ZPI=Conditional Halt
break;
case 0x18: // 3011: SFI=Store for Interrupt
this.storeForInterrupt(0);
break;
case 0x1C: // 3411: SFT=Store for Test
this.storeForInterrupt(1);
break;
case 0x21: // 4111: IP1=Initiate Processor 1
if (!this.NCSF) { // control-state only
this.initiate(0);
}
break;
case 0x22: // 4211: IP2=Initiate Processor 2
if (!this.NCSF) { // control-state only
this.M = 0x08; // INCW is stored in @10
if (this.BROF && !this.AROF) {
this.access(0x0D); // [M] = B
this.BROF = 0;
} else {
this.adjustAFull();
this.access(0x0C); // [M] = A
this.AROF = 0;
}
this.cc.initiateP2();
this.cycleLimit = 0; // give P2 a chance to run
}
break;
case 0x24: // 4411: IIO=Initiate I/O
if (!this.NCSF) {
this.M = 0x08; // address of IOD is stored in @10
if (this.BROF && !this.AROF) {
this.access(0x0D); // [M] = B
this.BROF = 0;
} else {
this.adjustAFull();
this.access(0x0C); // [M] = A
this.AROF = 0;
}
this.cc.initiateIO(); // let CentralControl choose the I/O Unit
this.cycleLimit = 0; // give the I/O a chance to start
}
break;
case 0x29: // 5111: IFT=Initiate For Test
if (!this.NCSF) { // control-state only
this.initiate(1);
}
break;
} // end switch for XX11 ops
break;
case 0x0D: // XX15: logical (bitmask) ops
switch (variant) {
case 0x01: // 0115: LNG=logical negate
this.adjustAFull();
t1 = this.A % 0x1000000;
t2 = (this.A - t1) / 0x1000000;
this.A = (t2 ^ 0x7FFFFF)*0x1000000 + (t1 ^ 0xFFFFFF);
break;
case 0x02: // 0215: LOR=logical OR
this.adjustABFull();
t1 = this.A % 0x1000000;
t2 = (this.A - t1) / 0x1000000;
t3 = this.B % 0x1000000;
t4 = (this.B - t3) / 0x1000000;
this.A = (t4 | (t2 & 0x7FFFFF))*0x1000000 + (t1 | t3);
this.BROF = 0;
break;
case 0x04: // 0415: LND=logical AND
this.adjustABFull();
t1 = this.A % 0x1000000;
t2 = (this.A - t1) / 0x1000000;
t3 = this.B % 0x1000000;
t4 = (this.B - t3) / 0x1000000;
this.A = ((t4 & 0x7FFFFF) | (t2 & t4 & 0x7FFFFF))*0x1000000 + (t1 & t3);
this.BROF = 0;
break;
case 0x08: // 1015: LQV=logical EQV
this.cycleCount += 8;
this.adjustABFull();
t1 = this.A % 0x1000000;
t2 = (this.A - t1) / 0x1000000;
t3 = this.B % 0x1000000;
t4 = (this.B - t3) / 0x1000000;
this.B = ((t4 & 0x7FFFFF) | ((~(t2 ^ t4)) & 0x7FFFFF))*0x1000000 + ((~(t1 ^ t3)) & 0xFFFFFF);
this.AROF = 0;
break;
case 0x10: // 2015: MOP=reset flag bit (make operand)
this.adjustAFull();
if (this.A >= 0x800000000000) {
this.A %= 0x800000000000;
}
break;
case 0x20: // 4015: MDS=set flag bit (make descriptor)
this.adjustAFull();
if (this.A < 0x800000000000) {
this.A += 0x800000000000;
}
break;
}
break;
case 0x11: // XX21: load & store ops
switch (variant) {
case 0x01: // 0121: CID=Conditional integer store descructive
break;
case 0x02: // 0221: CIN=Conditional integer store nondestructive
break;
case 0x04: // 0421: STD=Store destructive
break;
case 0x08: // 1021: SND=Store nondestructive
break;
case 0x10: // 2021: LOD=Load operand
break;
case 0x21: // 4121: ISD=Integer store destructive
break;
case 0x22: // 4221: ISN=Integer store nondestructive
break;
}
break;
case 0x15: // XX25: comparison & misc. stack ops
switch (variant) {
case 0x01: // 0125: GEQ=compare B greater or equal to A
this.B = (this.singlePrecisionCompare() >= 0 ? 1 : 0);
break;
case 0x02: // 0225: GTR=compare B greater to A
this.B = (this.singlePrecisionCompare() > 0 ? 1 : 0);
break;
case 0x04: // 0425: NEQ=compare B not equal to A
this.B = (this.singlePrecisionCompare() != 0 ? 1 : 0);
break;
case 0x08: // 1025: XCH=exchange TOS words
this.exchangeTOS();
break;
case 0x0C: // 1425: FTC=F field to core field
break;
case 0x10: // 2025: DUP=Duplicate TOS
if (this.AROF) {
this.AdjustBEmpty();
this.B = this.A;
this.BROF = 1;
} else {
this.adjustBFull();
this.A = this.B;
this.AROF = 1;
}
break;
case 0x1C: // 3425: FTF=F field to F field
break;
case 0x21: // 4125: LEQ=compare B less or equal to A
this.B = (this.singlePrecisionCompare() <= 0 ? 1 : 0);
break;
case 0x22: // 4225: LSS=compare B less to A
this.B = (this.singlePrecisionCompare() < 0 ? 1 : 0);
break;
case 0x24: // 4425: EQL=compare B equal to A
this.B = (this.singlePrecisionCompare() == 0 ? 1 : 0);
break;
case 0x2C: // 5425: CTC=core field to C field
break;
case 0x3C: // 7425: CTF=core field to F field
break;
}
break;
case 0x19: // XX31: branch, sign-bit, interrogate ops
switch (variant) {
case 0x01: // 0131: BBC=branch backward conditional
break;
case 0x02: // 0231: BFC=branch forward conditional
break;
case 0x04: // 0431: SSN=set sign bit (set negative)
this.adjustAFull();
t1 = this.A % 0x400000000000;
t2 = (this.A - t1)/0x400000000000;
this.A = ((t2 & 0x03) | 0x01)*0x400000000000 + t1;
break;
case 0x08: // 1031: CHS=change sign bit
this.adjustAFull();
t1 = this.A % 0x400000000000;
t2 = (this.A - t1)/0x400000000000;
this.A = ((t2 & 0x03) ^ 0x01)*0x400000000000 + t1;
break;
case 0x10: // 2031: TOP=test flag bit (test for operand)
this.adjustAEmpty();
this.adjustBFull();
this.A = (this.B % 0x800000000000 ? 0 : 1);
this.AROF = 1;
break;
case 0x11: // 2131: LBC=branch backward word conditional
break;
case 0x12: // 2231: LFC=branch forward word conditional
break;
case 0x14: // 2431: TUS=interrogate peripheral status
this.adjustAEmpty();
this.A = this.cc.interrogateUnitStatus();
this.AROF = 1;
break;
case 0x21: // 4131: BBW=branch backward unconditional
break;
case 0x22: // 4231: BFW=branch forward unconditional
break;
case 0x24: // 4431: SSP=reset sign bit (set positive)
this.adjustAFull();
t1 = this.A % 0x400000000000;
t2 = (this.A - t1)/0x400000000000;
this.A = (t2 & 0x02)*0x400000000000 + t1;
break;
case 0x31: // 6131: LBU=branch backward word unconditional
break;
case 0x32: // 6231: LFU=branch forward word unconditional
break;
case 0x34: // 6431: TIO=interrogate I/O channel
this.adjustAEmpty();
this.A = this.cc.interrogateIOChannel();
this.AROF = 1;
break;
case 0x38: // 7031: FBS=stack search for flag
// Handbook (bit numbers not reversed!):
// M + 1, Load A @ M; // why is this incrementing here?
// A48 & A46 <- 1
// A47 <- 0, A[45=>16] <- 0;
// A[15=>1] <- M
// RefMan:
// stack pop? // described as "Pushup into A occurs if necessary..."
// isolate lowest 15-bits of TOS // is this A?
// loop
// examine word at this base address
// if flag bit(0) is true, place address in A, present bit(2) is set, exit loop
// else increment address
// end loop
this.AROF = 1;
break;
}
break;
case 0x1D: // XX35: exit & return ops
switch (variant) {
case 0x01: // 0135: BRT=branch return
adjustAEmpty();
if (!this.BROF) {
this.Q |= 0x04; // Q03F: not used, except for display purposes
adjustBFull();
}
if (this.presenceTest(this.B)) {
this.S = (this.B % 0x40000000) >>> 15;
this.C = this.B % 0x8000;
this.access(0x30); // P = [C]
this.L = 0;
this.access(0x03); // B = [S], fetch MSCW
this.S--;
this.applyMSCW(this.B);
this.BROF = 0;
}
break;
case 0x02: // 0235: RTN=return normal
this.adjustAFull();
this.S = this.F;
this.access(0x03); // B = [S], fetch the RCW
switch (this.exitSubroutine(0)) {
case 0:
this.X = 0;
operandCall();
case 1:
this.Q |= 0x10; // set Q05F, for display only
this.X = 0;
descriptorCall();
}
break;
case 0x04: // 0435: XIT=exit procedure
this.AROF = 0;
this.S = this.F;
this.access(0x03); // B = [S], fetch the RCW
this.exitSubroutine(0);
break;
case 0x0A: // 1235: RTS=return special
this.adjustAFull();
this.access(0x03); // B = [S], fetch the RCW
switch (this.exitSubroutine(0)) {
case 0:
this.X = 0;
operandCall();
case 1:
this.Q |= 0x10; // set Q05F, for display only
this.X = 0;
descriptorCall();
case 2: // flag-bit interrupt occurred, do nothing
break;
}
break;
}
break;
case 0x21: // XX41: index, mark stack, etc.
switch (variant) {
case 0x01: // 0141: INX=index
this.adjustABFull();
t1 = this.A % 0x8000;
this.M = (t1 + this.B % 0x8000) & 0x7FFF;
this.A += this.M - t1;
this.BROF = 0;
break;
case 0x02: // 0241: COC=construct operand call
this.exchangeTOS();
this.A = this.cc.bitSet(this.A, 0);
this.operandCall();
break;
case 0x04: // 0441: MKS=mark stack
this.adjustAEmpty();
this.adjustBEmpty();
this.B = this.buildMSCW();
this.adjustBEmpty();
this.F = this.S;
if (!this.MSFF) {
if (this.SALF) { // store the MSCW at R+7
this.M = (this.R*64) + 7;
this.access(0x0D); // [M] = B
}
this.MSFF = 1;
}
break;
case 0x0A: // 1241: CDC=construct descriptor call
this.exchangeTOS();
this.A = this.cc.bitSet(this.A, 0);
this.descriptorCall();
break;
case 0x11: // 2141: SSF=F & S register set/store
break;
case 0x15: // 2541: LLL=link list lookup
break;
case 0x24: // 4441: CMN=enter character mode inline
this.enterCharModeInline();
break;
}
break;
case 0x25: // XX45: ISO=Variable Field Isolate op
this.adjustAFull();
t2 = variant >>> 3; // number of whole chars
if (t2) {
t1 = this.G*6 + this.H; // starting source bit position
t2 = t2*6 - (variant & 7); // number of bits
if (t1+t2 <= 48) {
this.A = this.cc.fieldIsolate(this.A, t1, t2);
} else { // handle wrap-around in the source value
this.A = this.cc.fieldInsert(
this.cc.fieldIsolate(this.A, 96-t1-t2, t1+t2-48), 48-t2, 48-t1,
this.cc.fieldIsolate(this.A, 0, 48-t1));
}
// approximate the shift cycle counts
this.cycleCount += (variant >>> 3) + (variant & 7) + this.G + this.H;
this.G = (this.G + variant >>> 3) & 7;
this.H = 0;
}
break;
case 0x29: // XX51: delete & conditional branch ops
if (variant == 0) { // 0051=DEL: delete TOS
if (this.AROF) {
this.AROF = 0;
} else if (this.BROF) {
this.BROF = 0;
} else {
this.S--;
}
} else {
switch (variant & 0x03) {
case 0x00: // X051/X451: CFN=non-zero field branch forward nondestructive
break;
case 0x01: // X151/X551: CBN=non-zero field branch backward nondestructive
break;
case 0x02: // X251/X651: CFD=non-zero field branch forward destructive
break;
case 0x03: // X351/X751: CBD=non-zero field branch backward destructive
break;
}
}
break;
case 0x2D: // XX55: NOP & DIA=Dial A ops
if (opcode & 0xFC0) {
this.G = variant >>> 3;
this.H = (variant) & 7;
// else // 0055: NOP=no operation (the official one, at least)
}
break;
case 0x31: // XX61: XRT & DIB=Dial B ops
if (opcode & 0xFC0) {
this.K = variant >>> 3;
this.V = (variant) & 7;
} else { // 0061=XRT: temporarily set full PRT addressing mode
this.VARF = this.SALF;
this.SALF = 0;
}
break;
case 0x35: // XX65: TRB=Transfer Bits
this.adjustABFull();
t1 = this.G*6 + this.H; // A register starting bit nr
if (t1+variant > 48) {
variant = 48-t1;
}
t2 = this.K*6 + this.V; // B register starting bit nr
if (t2+variant > 48) {
variant = 48-t2;
}
if (variant > 0) {
this.B = this.cc.fieldTransfer(this.B, t2, variant, this.A, t1);
}
this.AROF = 0;
this.cycleCount += variant + this.G + this.K; // approximate the shift counts
break;
case 0x39: // XX71: FCL=Compare Field Low
this.adjustABFull();
t1 = this.G*6 + this.H; // A register starting bit nr
if (t1+variant > 48) {
variant = 48-t1;
}
t2 = this.K*6 + this.V; // B register starting bit nr
if (t2+variant > 48) {
variant = 48-t2;
}
if (variant > 0 && (this.cc.fieldIsolate(this.B, t2, variant) < this.cc.fieldIsolate(this.A, t1, variant))) {
this.A = 1;
} else {
this.A = 0;
}
this.cycleCount += variant + this.G + this.K; // approximate the shift counts
break;
case 0x3D: // XX75: FCE=Compare Field Equal
this.adjustABFull();
t1 = this.G*6 + this.H; // A register starting bit nr
if (t1+variant > 48) {
variant = 48-t1;
}
t2 = this.K*6 + this.V; // B register starting bit nr
if (t2+variant > 48) {
variant = 48-t2;
}
if (variant > 0 && (this.cc.fieldIsolate(this.B, t2, variant) == this.cc.fieldIsolate(this.A, t1, variant))) {
this.A = 1;
} else {
this.A = 0;
}
this.cycleCount += variant + this.G + this.K; // approximate the shift counts
break;
default:
break; // anything else is a no-op
} // end switch for non-LITC/OPDC/DESC operators
break;
} // end switch for word-mode operators
} // end main switch for opcode dispatch
/***************************************************************
* SECL: Syllable Execution Complete Level *
***************************************************************/
if ((this === this.cc.P1 ? this.cc.IAR : this.I) && this.NCSF) {
// there's an interrupt and we're in normal state
this.T = 0x0609; // inject 3011=SFI into T
this.Q |= 0x40 // set Q07F to indicate hardware-induced SFI
this.Q &= ~(0x100); // reset Q09F: adder mode for R-relative addressing
} else {
// otherwise, fetch the next instruction
switch (this.L) {
case 0:
this.T = ((this.P - this.P % 0x1000000000) / 0x1000000000) % 0x1000;
this.L = 1;
break;
case 1:
this.T = ((this.P - this.P % 0x1000000) / 0x1000000) % 0x1000;
this.L = 2;
break;
case 2:
this.T = ((this.P - this.P % 0x1000) / 0x1000) % 0x1000;
this.L = 3;
break;
case 3:
this.T = this.P % 0x1000;
this.L = 0;
this.C++;
this.access(0x30); // P = [C]
break;
}
}
} while ((this.cycleCount += 2) < this.cycleLimit && this.busy);
};
/**************************************/
B5500Processor.prototype.schedule = function schedule() {
/* Schedules the processor run time and attempts to throttle performance
to approximate that of a real B5500. Well, at least we hope this will run
fast enough that the performance will need to be throttled. It establishes
a timeslice in terms of a number of processor "cycles" of 1 microsecond
each and calls run() to execute at most that number of cycles. run()
counts up cycles until it reaches this limit or some terminating event
(such as a halt), then exits back here. If the processor remains active,
this routine will reschedule itself for an appropriate later time, thereby
throttling the performance and allowing other modules a chance at the
Javascript execution thread. */
var delayTime;
var that = schedule.that;
that.scheduler = null;
that.cycleLimit = B5500Processor.timeSlice;
that.cycleCount = 0;
that.run();
that.totalCycles += that.cycleCount
that.procTime += that.cycleCount;
if (that.busy) {
delayTime = that.procTime/1000 - new Date().getTime();
that.procSlack += delayTime;
that.scheduler = setTimeout(that.schedule, (delayTime < 0 ? 1 : delayTime));
}
};
/**************************************/
B5500Processor.prototype.step = function() {
/* Single-steps the processor. Normally this will cause one instruction to
be executed, but note that in case of an interrupt, one or two injected
instructions (e.g., SFI followed by ITI) could also be executed. */
this.cycleLimit = 1;
this.cycleCount = 0;
this.run();
this.totalCycles += this.cycleCount
this.procTime += this.cycleCount;
};
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