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pkimpel.retro-b5500/emulator/B5500CentralControl.js

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/***********************************************************************
* retro-b5500/emulator B5500CentralControl.js
************************************************************************
* Copyright (c) 2012, Nigel Williams and Paul Kimpel.
* Licensed under the MIT License, see http://www.opensource.org/licenses/mit-license.php
************************************************************************
* JavaScript object definition for the B5500 Central Control module.
************************************************************************
* 2012-06-03 P.Kimpel
* Original version, from thin air.
***********************************************************************/
/**************************************/
function B5500CentralControl() {
/* Constructor for the Central Control module object */
/* Global system modules */
this.PA = null; // Processor A (PA)
this.PB = null; // Processor B (PB)
this.IO1 = null; // I/O unit 1
this.IO2 = null; // I/O unit 2
this.IO3 = null; // I/O unit 3
this.IO4 = null; // I/O unit 4
this.P1 = null; // Reference for Processor 1 (control) [PA or PB]
this.P1 = null; // Reference for Processor 2 (slave) [PA or PB]
this.AddressSpace = []; // Array of memory module address spaces (8 x 32KB each)
this.Memory = []; // Array of memory module words as Float64s (8 x 4KW each)
// This memory instantiation should be done in configuration, but here's the idea...
this.AddressSpace[0] = new ArrayBuffer(32768);
this.Memory[0] = new Float64Array(this.AddressSpace[0]);
this.PB1L = 0; // 0=> PA is P1, 1=> PB is P1
this.cardLoadSelect = 0; // 0=> load from disk/drum; 1=> load from cards
this.nextTimeStamp = 0; // Next actual Date.getTime() expected
this.timer = null; // Reference to the RTC setTimeout id.
this.loadTimer = null; // Reference to the load setTimeout id.
this.tock.that = this; // Establish contexts for when called from setTimeout().
this.loadComplete.that = this;
this.clear(); // Create and initialize the Central Control state
}
/**************************************/
/* Global constants */
B5500CentralControl.rtcTick = 1000/60; // Real-time clock period, milliseconds
B5500CentralControl.pow2 = [ // powers of 2 from 0 to 52
1, 2, 4, 8,
16, 32, 64, 128,
256, 512, 1024, 2048,
4096, 8192, 16384, 32768,
65536, 131072, 262144, 524288,
1048576, 2097152, 4194304, 8388608,
16777216, 33554432, 67108864, 134217728,
268435456, 536870912, 1073741824, 2147483648,
4294967296, 8589934592, 17179869184, 34359738368,
68719476736, 137438953472, 274877906944, 549755813888,
1099511627776, 2199023255552, 4398046511104, 8796093022208,
17592186044416, 35184372088832, 70368744177664, 140737488355328,
281474976710656, 562949953421312, 1125899906842624, 2251799813685248,
4503599627370496];
B5500CentralControl.mask2 = [ // (2**n)-1 for n from 0 to 52
0, 1, 3, 7,
15, 31, 63, 127,
255, 511, 1023, 2047,
4095, 8191, 16383, 32767,
65535, 131071, 262143, 524287,
1048575, 2097151, 4194303, 8388607,
16777215, 33554431, 67108863, 134217727,
268435455, 536870911, 1073741823, 2147483647,
4294967295, 8589934591, 17179869183, 34359738367,
68719476735, 137438953471, 274877906943, 549755813887,
1099511627775, 2199023255551, 4398046511103, 8796093022207,
17592186044415, 35184372088831, 70368744177663, 140737488355327,
281474976710655, 562949953421311, 1125899906842623, 2251799813685247,
4503599627370495];
/**************************************/
B5500CentralControl.prototype.clear = function() {
/* Initializes the system and starts the real-time clock */
if (this.timer) {
clearTimeout(this.timer);
}
this.nextTimeStamp = new Date().getTime() + B5500CentralControl.rtcTick;
this.timer = setTimeout(this.tock, B5500CentralControl.rtcTick);
this.IAR = 0; // Interrupt address register
this.TM = 0; // Real-time clock (6 bits, 60 ticks per second)
this.CCI03F = 0; // Time interval interrupt
this.CCI04F = 0; // I/O busy interrupt
this.CCI05F = 0; // Keyboard request interrupt
this.CCI06F = 0; // Printer 1 finished interrupt
this.CCI07F = 0; // Printer 2 finished interrupt
this.CCI08F = 0; // I/O unit 1 finished interrupt (RD in @14)
this.CCI09F = 0; // I/O unit 2 finished interrupt (RD in @15)
this.CCI10F = 0; // I/O unit 3 finished interrupt (RD in @16)
this.CCI11F = 0; // I/O unit 4 finished interrupt (RD in @17)
this.CCI12F = 0; // P2 busy interrupt
this.CCI13F = 0; // Remote inquiry request interrupt
this.CCI14F = 0; // Special interrupt #1 (not used)
this.CCI15F = 0; // Disk file #1 read check finished
this.CCI16F = 0; // Disk file #2 read check finished
this.MCYF = 0; // Memory cycle FFs (one bit per M0..M7)
this.PAXF = 0; // PA memory exchange select (M0..M7)
this.PBXF = 0; // PB memory exchange select (M0..M7)
this.I1XF = 0; // I/O unit 1 exchange select (M0..M7)
this.I2XF = 0; // I/O unit 2 exchange select (M0..M7)
this.I3XF = 0; // I/O unit 3 exchange select (M0..M7)
this.I4XF = 0; // I/O unit 4 exchange select (M0..M7)
this.AD1F = 0; // I/O unit 1 busy
this.AD2F = 0; // I/O unit 2 busy
this.AD3F = 0; // I/O unit 3 busy
this.AD4F = 0; // I/O unit 4 busy
this.LOFF = 0; // Load button pressed on console
this.CTMF = 0; // Commence timing FF
this.P2BF = 0; // Processor 2 busy FF
this.HP2F = 1; // Halt processor 2 FF
if (this.PA) {
this.PA.clear();
}
if (this.PB) {
this.PB.clear();
}
this.P1 = (this.PB1L ? this.PB : this.PA);
this.P2 = (this.PB1L ? this.PA : this.PB);
if (!this.P2) {
this.P2BF = 1; // mark non-existent P2 as busy
}
}
/**************************************/
B5500CentralControl.prototype.bit = function(word, bit) {
/* Extracts and returns the specified bit from the word */
var e = 47-bit;
var p;
if (e > 0( {
p = B5500CentralControl.pow2[e];
return ((word - word%p)/p) % 2;
} else {
return word % 2;
}
}
/**************************************/
B5500CentralControl.prototype.bitSet = function(word, bit) {
/* Sets the specified bit in word and returns the updated word */
return this.fieldInsert(word, bit, 1, 1);
}
/**************************************/
B5500CentralControl.prototype.bitReset = function(word, bit) {
/* Resets the specified bit in word and returns the updated word */
return this.fieldInsert(word, bit, 1, 0);
}
/**************************************/
B5500CentralControl.prototype.fieldIsolate = function(word, start, width) {
/* Extracts a bit field [start:width] from word and returns the field */
var ue = 48-start; // upper power exponent
var le = ue-width; // lower power exponent
var p;
if (le > 0) {
p = B5500CentralControl.pow2[le];
return ((word - word%p)/p) % B5500CentralControl.pow2[width];
} else {
return word % B5500CentralControl.pow2[width];
}
}
/**************************************/
B5500CentralControl.prototype.fieldInsert = function(word, start, width, value) {
/* Inserts a bit field into word.[start:width] and returns the updated word */
var ue = 48-start; // upper power exponent
var le = ue-width; // lower power exponent
var bpower = 1; // bottom portion power of 2
var bottom = 0; // unaffected bottom portion of word
var top = 0; // unaffected top portion of word
if (start > 0) {
top = word - (word % B5500CentralControl.pow2[ue]);
}
if (le > 0) {
bpower = B5500CentralControl.pow2[le];
bottom = word % bpower;
}
return (value % B5500CentralControl.pow2[width])*bpower + top + bottom;
}
/**************************************/
B5500CentralControl.prototype.fetch = function(r) {
/* Called by requestor module "r" to fetch a word from memory. */
var acer = r.accessor;
var addr = acer.addr;
var modNr = addr >>> 12;
var modAddr = addr & 0x0FFF;
var modMask = 1 << modNr;
this.MCYF |= modMask; // !! need to figure out when to turn this off for display purposes
// (odd/even addresses? fetch vs. store? XOR the mask?)
switch (r) {
case PA:
this.PAXF = modMask;
break;
case PB:
this.PBXF = modMask;
break;
case IO1:
this.I1XF = modMask;
break;
case IO2:
this.I2XF = modMask;
break;
case IO3:
this.I3XF = modMask;
break;
case IO4:
this.I4XF = modMask;
break;
}
// For now, we assume memory parity can never happen
if (acer.MAIL || !this.Memory[modNr]) {
acer.MPED = 0;
acer.MAED = 1;
// no .word value is returned in this case
} else {
acer.MPED = 0;
acer.MAED = 0;
acer.word = this.Memory[memMod][modAddr];
}
}
/**************************************/
B5500CentralControl.prototype.store = function(r, addr, word) {
/* Called by requestor module "r" to store a word into memory. */
var acer = r.accessor
var addr = acer.addr;
var modNr = addr >>> 12;
var modAddr = addr & 0x0FFF;
var modMask = 1 << modNr;
this.MCYF |= modMask; // !! need to figure out when to turn this off for display purposes
// (odd/even addresses? fetch vs. store? XOR the mask?)
switch (r) {
case this.PA:
this.PAXF = modMask;
break;
case this.PB:
this.PBXF = modMask;
break;
case this.IO1:
this.I1XF = modMask;
break;
case this.IO2:
this.I2XF = modMask;
break;
case this.IO3:
this.I3XF = modMask;
break;
case this.IO4:
this.I4XF = modMask;
break;
}
// For now, we assume memory parity can never happen
if (acer.MAIL || !this.Memory[modNr]) {
acer.MPED = 0;
acer.MAED = 1;
} else {
acer.MPED = 0;
acer.MAED = 0;
this.Memory[memMod][modAddr] = acer.word;
}
}
/**************************************/
B5500CentralControl.prototype.signalInterrupt = function() {
/* Called by all modules to signal that an interrupt has occurred and
to invoke the interrupt prioritization mechanism. This will result in
an updated vector address in the IAR. Can also be called to reprioritize
any remaining interrupts after an interrupt is handled. If no interrupt
condition exists, this.IAR is set to zero. */
var p1 = this.P1;
var p2 = this.P2;
this.IAR = p1.I & 0x01 ? 0x30 // @60: P1 memory parity error
: p1.I & 0x02 ? 0x31 // @61: P1 invalid address error
: this.CCI03F ? 0x12 // @22: Time interval
: this.CCI04F ? 0x13 // @23: I/O busy
: this.CCI05F ? 0x14 // @24: Keyboard request
: this.CCI08F ? 0x17 // @27: I/O 1 finished
: this.CCI09F ? 0x18 // @30: I/O 2 finished
: this.CCI10F ? 0x19 // @31: I/O 3 finished
: this.CCI11F ? 0x1A // @32: I/O 4 finished
: this.CCI06F ? 0x15 // @25: Printer 1 finished
: this.CCI07F ? 0x16 // @26: Printer 2 finished
: this.CCI12F ? 0x1B // @33: P2 busy
: this.CCI13F ? 0x1C // @34: Inquiry request
: this.CCI14F ? 0x1D // @35: Special interrupt 1
: this.CCI15F ? 0x1E // @36: Disk file 1 read check finished
: this.CCI16F ? 0x1F // @37: Disk file 2 read check finished
: p1.I & 0x04 ? 0x32 // @62: P1 stack overflow
: p1.I & 0xF0 ? (p1.I >>> 4) + 0x30 // @64-75: P1 syllable-dependent
: p2.I & 0x01 ? 0x20 // @40: P2 memory parity error
: p2.I & 0x02 ? 0x21 // @41: P2 invalid address error
: p2.I & 0x04 ? 0x22 // @42: P2 stack overflow
: p2.I & 0xF0 ? (p2.I >>> 4) + 0x20 // @44-55: P2 syllable-dependent
: 0; // no interrupt set
}
/**************************************/
B5500CentralControl.prototype.clearInterrupt = function() {
/* Resets an interrupt based on the current setting of this.IAR, then
reprioritizes any remaining interrupts, leaving the new vector address
in this.IAR. */
var p1 = this.P1;
var p2 = this.P2;
switch (this.IAR) {
case 0x12: // @22: Time interval
this.CCI03F = 0;
break;
case 0x13: // @23: I/O busy
this.CCI04F = 0;
break;
case 0x14: // @24: Keyboard request
this.CCI05F = 0;
break;
case 0x15: // @25: Printer 1 finished
this.CCI06F = 0;
break;
case 0x16: // @26: Printer 2 finished
this.CCI07F = 0;
break;
case 0x17: // @27: I/O 1 finished
this.CCI08F = 0;
break;
case 0x18: // @30: I/O 2 finished
this.CCI09F = 0;
break;
case 0x19: // @31: I/O 3 finished
this.CCI10F = 0;
break;
case 0x1A: // @32: I/O 4 finished
this.CCI11F = 0;
break;
case 0x1B: // @33: P2 busy
this.CCI12F = 0;
break;
case 0x1C: // @34: Inquiry request
this.CCI13F = 0;
break;
case 0x1D: // @35: Special interrupt 1
this.CCI14F = 0;
break;
case 0x1E: // @36: Disk file 1 read check finished
this.CCI15F = 0;
break;
case 0x1F: // @37: Disk file 2 read check finished
this.CCI16F = 0;
break;
case 0x20: // @40: P2 memory parity error
p2.I &= 0xFE;
break;
case 0x21: // @41: P2 invalid address error
p2.I &= 0xFD;
break;
case 0x22: // @42: P2 stack overflow
p2.I &= 0xFB;
break;
case 0x24: // @44-55: P2 syllable-dependent
case 0x25:
case 0x26:
case 0x27:
case 0x28:
case 0x29:
case 0x2A:
case 0x2B:
case 0x2C:
case 0x2D:
p2.I &= 0x0F;
break;
case 0x30: // @60: P1 memory parity error
p1.I &= 0xFE;
break;
case 0x31: // @61: P1 invalid address error
p1.I &= 0xFD;
break;
case 0x32: // @62: P1 stack overflow
p1.I &= 0x0B;
break;
case 0x34: // @64-75: P1 syllable-dependent
case 0x35:
case 0x36:
case 0x37:
case 0x38:
case 0x39:
case 0x3A:
case 0x3B:
case 0x3C:
case 0x3D:
p1.I &= 0x0F;
break;
default: // no interrupt vector was set
break;
}
this.signalInterrupt();
}
/**************************************/
B5500CentralControl.prototype.tock = function tock() {
/* Handles the 1/60th second real-time clock tick */
var that = tock.that; // capture the current closure context
var thisTime = new Date().getTime();
if (that.TM < 63) {
that.TM++;
} else {
that.TM = 0;
that.CCI03F = 1; // set timer interrupt
// inhibit for now // that.signalInterrupt();
}
that.nextTimeStamp += B5500CentralControl.rtcTick;
that.timer = setTimeout(function() {that.tock()},
(that.nextTimeStamp < thisTime ? 0 : that.nextTimeStamp-thisTime));
}
/**************************************/
B5500CentralControl.prototype.initiateP2 = function() {
/* Called by P1 to initiate P2. Assumes that an INCW has been stored at
memory location @10. If P2 is busy or not present, sets the P2 busy
interrupt. Otherwise, loads the INCW into P2's A register and initiates
the processor. */
var p2 = this.P2;
if (!this.P2 || this.P2BF) {
this.CCI12F = 1; // set P2 busy interrupt
this.signalInterrupt();
} else {
p2.M = 8; // Now have P2 pick up the INCW
p2.access(0x04); // A = [M]
p2.AROF = 1;
p2.T = 0x849; // inject 4111=IP1 into P2's T register
p2.TROF = 1;
p2.NCSF = 0; // make sure P2 is in control state
this.P2BF = 1;
this.HP2F = 0;
// Now start scheduling P2 on the Javascript thread
p2.procTime = new Date().getTime()*1000;
p2.scheduler = setTimeout(p2.schedule, 0);
}
}
/**************************************/
B5500CentralControl.prototype.initiateIO = function() {
/* Selects an I/O unit and initiates an I/O */
if (this.IO1) {
this.AD1F = 1;
IO1.initiate();
} else if (this.IO2) {
this.AD2F = 1;
IO2.initiate();
} else if (this.IO3) {
this.AD3F = 1;
IO3.initiate();
} else if (this.IO4) {
this.AD4F = 1;
IO4.initiate();
} else {
this.CCI04F = 1; // set I/O busy interrupt
this.signalInterrupt();
}
}
/**************************************/
B5500CentralControl.prototype.halt = function() {
/* Halts the processors. Any in-process I/Os are allowed to complete */
if (this.PA && this.PA.busy) {
this.PA.busy = false;
this.PA.cycleLimit = 0;
if (this.PA.scheduler) {
clearTimeout(this.PA.scheduler);
this.PA.scheduler = null;
}
}
if (this.PB && this.PB.busy) {
this.PB.busy = false;
this.PB.cycleLimit = 0;
if (this.PB.scheduler) {
clearTimeout(this.PB.scheduler);
this.PB.scheduler = null;
}
}
if (this.loadTimer) {
cancelTimeout(this.loadTimer);
this.loadTimer = null;
}
}
/**************************************/
B5500CentralControl.prototype.load = function() {
/* Initiates a Load operation to start the system */
if ((this.PA && this.PA.busy) || (this.PB && this.PB.busy)) {
this.clear();
if (this.P1) {
this.LOFF = 1;
if (this.IO1) { // !! not sure about I/O selection here
IO1.initiateLoad(this.cardLoadSelect);
this.loadComplete();
}
}
}
}
/**************************************/
B5500CentralControl.prototype.loadComplete = function loadComplete() {
/* Monitors an initial load I/O operation for complete status.
When complete, initiates P1 */
var that = loadComplete.that; // capture the current closure context
if (!that.CCI08F) {
that.loadTimer = setTimeout(that.loadComplete, 10);
} else {
that.loadTimer = null
that.LOFF = 0;
that.P1.C = 0x10; // execute from address @20
that.P1.L = 0;
that.P1.access(0x30); // P = [C]
that.P1.T = Math.floor(that.P / 0x1000000000) % 0x1000;
that.P1.TROF = 1;
// Now start scheduling P1 on the Javascript thread
that.P1.procTime = new Date().getTime()*1000;
that.P1.scheduler = setTimeout(that.P1.schedule, 0);
}
}
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