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Merge pull request #11 from philbudne/master
update, extend asm_syntax.txt (intro to PDP-7 programming) as7 fixes fix some system, trysys typos add some system comments (tab separated)
This commit is contained in:
philbudne
@@ -1,42 +1,273 @@
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Basics of the Unix assembler syntax
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Basics of the "Unix v0" 'as' assembler syntax and PDP-7 coding:
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Lines starting with " are comment lines
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ASSEMBLER SYNTAX:
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=================
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Anything from " to end of line is a comment.
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. is the location counter, where the next code or constant will be placed
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.. is the relocation counter
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.. is the relocation counter (not currently handled)
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t = 0 Sets a built-in variable to this value without generating any machine code.
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Variables so far are . .. and t. Not sure what t's purpose is yet.
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Symbol names start with a letter, and can contain letters and "."
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The dump of label values in "scans/sysmap" appears to show truncation
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after 8 characters (not currently enforced by the "as7" Perl script).
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orig: is a label. It looks like labels can have dots in them.
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Dots seem to separate structures and fields, e.g. u.base
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but there are some symbols that start with dots, e.g. .seek
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symbol = expression
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jms copy; 10; u.rg+2; 6 Semicolons separate instructions and
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word expressions that follow the instruction
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Sets a built-in variable to this value without generating any
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machine code.
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Some expressions are 0:0, not sure about this.
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Is it two 9-bit fields? No idea
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as7 enters machine instructions and the indirect bit (i)
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into the variable table.
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jmp 1f Jump back to the closest 1: label
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jmp 1b Jump forward to the closest 1: label
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label: is a label.
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Some lines are indented differently to others e.g.
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single digit decimal numbers can be used as "local" labels,
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which are referenced with Nf and Nb:
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jms betwen; o10000; o17762
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jms error
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dac .+1
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jmp 1f Jump back to the closest 1: label
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jmp 1b Jump forward to the closest 1: label
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I think this is to indicate the skip logic, but it plays no part in the assembly syntax.
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-1 occurs instead of instructions, so it looks like the assembler allows
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literal constants at any time.
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multiple words can be entered on one line, separated by semi-colon.
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String literals seem to be two characters decorated with < > characters, e.g.
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"ab" is <a>b. I'm guessing these are placed as pairs in one word. The syntax
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is confusing, because I've also seen <no> ; 040 ; <fi> ; <le>; <s 012 which
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appears to mean "no files\n".
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Looks like a line can contain multiple labels, e.g. o12: d10: 10
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A line can contain multiple labels, e.g. o12: d10: 10
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Numeric literals: 0xx are octal values, [1-9]xx are decimal values.
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CONVENTIONS:
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============
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Because there is no immediate mode (and "as" lacks the literal syntax
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found in DEC assemblers), there is a convention for literal (manifest)
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constants:
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dNNN indicates the location of a constant for decimal NNN.
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oOOO for octal constant OOO.
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dmN (decimal minus) indicates a constant for decimal -N.
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High order bits of the "law" (load ac with word) instruction are all
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ones, so "-1" as an instruction loads -1 into AC.
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Subroutine arguments are often located in the words following the
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call. When an argument is a variable, sometimes a "0:" local label is
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used to tag the location:
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jms namei; 0:0
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Indentation is (sometimes) used to indicate an instruction
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or subroutine that may skip:
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jms betwen; o10000; o17762
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jms error
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dac .+1
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NOTE! the "betwen" (between) routine (which appears in multiple
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places) takes ADDRESSES of values (which can be literals, as above),
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or could be symbol names for variables.
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I haven't seen any cases where "skip chains" (sequences of skip
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instructions) are indicated by multiple indents.
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There is no hardware stack, so the only form of subroutine call (jms)
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is "impure" and leaves the (updated) program counter in the first word
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of the subroutine, and execution starts on the second word.
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Routines which fetch arguments from after the jms instruction may do:
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routine: 0
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lac routine i " pick up argument after jms
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dac temp " store in temp location
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isz routine " increment return PC to skip argument
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Routines which (optionally) skip (eg; on success) may use "isz
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routine" to (conditionally) increment the return PC.
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In the system code t is used as a (current) offset into a block of
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temporary location(s) for a routine or group of routines , at label
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9f, so you'll see:
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this:
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0
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lac 9f+t+N
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....
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t=t+M
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....
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that:
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0
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lac 9f+t+I
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....
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t=t+J
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.....
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.....
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.....
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9f:
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.=.+t
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HARDWARE:
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=========
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References:
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http://simh.trailing-edge.com/docs/architecture18b.pdf
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http://www.soemtron.org/pdp7.html
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http://www.soemtron.org/pdp7history.html
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NOTE! All opcodes are defined in "sop.s" (and in "as7") and are
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commented as below.
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The PDP-4/7/9/15 family started as a simplified version of the PDP-1,
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(itself an evolution of the TX-0, designed at MIT Lincoln Labs). The
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PDP-4 wasn't very successful (offering 5/8 PDP-1 performance at 1/2
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the price).
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The PDP-7 was originally concieved of as a repackaging of the PDP-1,
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but DEC had a built up more system software for the PDP-4 than for the
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PDP-1 (including a FORTRAN II compiler!), so they continued with the
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new architecture. See Bob's paper (first link above) for more detail.
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The Living Computing Museum in Seattle has a running PDP-7, and
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intends to build simulated disk hardware to enable running "Unix v0".
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Words are 18 bits, words are typically represented as six octal digits.
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There is one 18 bit accumulator, called "AC".
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The "LINK" register is a 1-bit register that is included in shifts.
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The Extended Arithmetic Element (EAE) option adds an "MQ" register which
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has limited uses.
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Bit numbering is "big endian": bit zero is 400000.
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There are no "addressing" modes: memory referencing instructions,
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(opcodes 0 thru 060) decode the low 14 bits as:
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I (020000) "indirect" bit
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Y (017777) 13-bit address field.
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When the "I" bit is clear, the "Y" field is the address of the operand.
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When the "I" bit is set, the word referenced by the contents of the
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word addressed by "Y" field is used as the operand.
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Unlike the PDP-1 (and PDP-6/10) indirect references are not
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multi-level, and end after the first indirect fetch.
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The PDP-7 found by Ken Thompson apparently did not have extended
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memory or memory protection options and could directly reference all
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8K words of memory (at all times).
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Unix system code appears to have resided in the low 4K of memory, and
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a single user program in the high 4K. The system had a "fast"
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fixed-head disk, but indirect memory access locks out DMA by the disk
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controller, and indirect access cannot be used while disk transfers
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are active (the interrupt service routines for clock and TTY, are
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coded without using indirect!). Because of this, disk access cannot
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be "overlapped" with user code, but users are free to use "indirect"
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freely.
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When locations 010 through 017 of memory are referenced *INDIRECTLY*,
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they auto-increment after access, and can be used as "index
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registers".
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System calls are made using the "CAL" (call) instruction (octal 00).
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The Y field indicates the system call number. "CAL" behaves like "jms
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020". "CAL" with the "I" bit set behaves like "jms 20 i". The system
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handler appears to deal with both (although the non-indirect form
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destroys the contents of location 020), and has a longer code path, so
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it seems likely that "sys=cal i" became the preferred system call at
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some point?
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The kernel preserves the contents of the users' AC and MQ registers
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and locations 8-15 in the "userdata" block (symbols u.ac, u.mq and
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u.rq). Location u.rq+8 is the saved PC of the last system call.
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The "save" system call (and any undefined system call) write high 4K
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of memory and the "userdata" block (to fd 1?????)
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The system did not have advanced interrupt processing hardware, so all
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"priority interrupts" (also known in the past as "address break"
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processing) dispatched as if a "jms 0" was executed, and are processed
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in the "pibreak" routine.
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Summary of memory instructions (from annotated sop.s):
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dac = 0040000 " MEM: deposit AC
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jms = 0100000 " MEM: jump to subroutine
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dzm = 0140000 " MEM: deposit zero to memory
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lac = 0200000 " MEM: load AC
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xor = 0240000 " MEM: XOR with AC
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add = 0300000 " MEM: one's complement add
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tad = 0340000 " MEM: two's complement add
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xct = 0400000 " MEM: execute
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isz = 0440000 " MEM: increment and skip if zero
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and = 0500000 " MEM: AND with memory
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sad = 0540000 " MEM: skip if AC different
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jmp = 0600000 " MEM: jump
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Other instruction groups do not interpret the "I" bit, and all begin
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with '7' in the high three bits.
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I/O Transfer (or IOT) have 111000 (070) in the high six bits. the next
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six bits (two octal digits) indicate the device number.
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Operate (OPR) which is "microcoded" with low order bits indicating
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"micro operations" to be performed have 11110 (074) in the high four
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bits:
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cma = 0740001 " OPR: complement AC
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ral = 0740010 " OPR: rotate AC left
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rar = 0740020 " OPR: rotate AC right
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hlt = 0740040 " OPR: halt
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sma = 0740100 " OPR: skip on minus AC
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sza = 0740200 " OPR: skip on zero AC
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snl = 0740400 " OPR: skip on non-zero link
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skp = 0741000 " OPR: skip unconditionally
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sna = 0741200 " OPR: skip on negative AC
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szl = 0741400 " OPR: skip on zero link
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rtl = 0742010 " OPR: rotate two left
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rtr = 0742020 " OPR: rotate two right
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cll = 0744000 " OPR: clear link
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rcl = 0744010 " OPR: clear link, rotate left
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rcr = 0744020 " OPR: clear link, rotate right
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cla = 0750000 " OPR: clear AC
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las = 0750004 " OPR: load AC from switches
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With some limitations, OPR instructions can be OR-ed together.
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(Ordering of operations is determined by the hardware, not by their
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order in the source!!):
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sna cla " skip on negative AC, clear AC
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sna spa " skip on negative or positive AC
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sna ral " skip on negative AC, rotate AC left
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cla cll sza " skip on AC zero, clear AC, clear LINK
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The last "operate" instruction is not microcoded:
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law = 0760000 " OPR: load accumulator with (instr)
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and as noted above, is often coded directly as an immediate negative constant.
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Unix v0 depends on the EAE option, which uses instructions with 064 in
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the top four bits, and is used for multiply, divide, and the 18-bit MQ
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register:
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lrs = 0640500 " EAE: long right shift
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lrss = 0660500 " EAE: long right shift, signed
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lls = 0640600 " EAE: long left shift
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llss = 0660600 " EAE: long left shift, signed
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|
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als = 0640700 " EAE: AC left shift
|
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alss = 0660700 " EAE: AC left shift, signed
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|
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mul = 0653323 " EAE: multiply
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idiv = 0653323 " EAE: integer divide
|
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|
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lacq = 0641002 " EAE: load AC with MQ
|
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clq = 0650000 " EAE: clear MQ
|
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omq = 0650002 " EAE: OR MQ into AC
|
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cmq = 0650004 " EAE: complement MQ
|
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lmq = 0652000 " EAE: load MQ from AC
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@@ -53,7 +53,7 @@ orig:
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jms halt
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okexit:
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dzm: u.ac
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dzm u.ac
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sysexit:
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ion
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lac .savblk
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@@ -72,7 +72,7 @@ sysexit:
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dac 9
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lac u.rq
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dac 8
|
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lac u.rq
|
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lac u.mq
|
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lmq
|
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lac u.ac
|
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jmp u.rq+8 i
|
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|
||||
@@ -32,7 +32,7 @@ error:
|
||||
1: 077012
|
||||
|
||||
a.out:
|
||||
<a.>;<ou><t 040; 040040
|
||||
<a.>;<ou>;<t 040; 040040
|
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t1: 0
|
||||
t2: 0
|
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c1: 0
|
||||
|
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86
src/sys/s1.s
86
src/sys/s1.s
@@ -21,61 +21,61 @@ orig:
|
||||
jmp 1f+1
|
||||
1f
|
||||
1: 0
|
||||
iof
|
||||
dac u.ac
|
||||
iof " interrupts off
|
||||
dac u.ac " save user AC
|
||||
lacq
|
||||
dac u.mq
|
||||
dac u.mq " save user MQ
|
||||
lac 8
|
||||
dac u.rq
|
||||
dac u.rq " save user auto-index location 8
|
||||
lac 9
|
||||
dac u.rq+1
|
||||
jms copy; 10; u.rq+2; 6
|
||||
lac 1b
|
||||
dac u.rq+8
|
||||
dac u.rq+1 " save user auto-index location 9
|
||||
jms copy; 10; u.rq+2; 6 " save user auto-index locations 10-15
|
||||
lac 1b " load user PC after system call
|
||||
dac u.rq+8 " save user PC
|
||||
-1 " load -1
|
||||
dac .savblk " set "save" flag (cleared by disk I/O?)
|
||||
dac .insys " set "in system" flag
|
||||
lac uquant " load user quantum count
|
||||
jms betwen; d0; maxquant " check if between 0 & maxquant??
|
||||
jms swap " no: swap processes
|
||||
ion " interrupts on
|
||||
-1
|
||||
dac .savblk
|
||||
dac .insys
|
||||
lac uquant
|
||||
jms betwen; d0; maxquant
|
||||
jms swap
|
||||
ion
|
||||
-1
|
||||
tad u.rq+8
|
||||
jms laci
|
||||
jms betwen; o20001; swn
|
||||
jmp badcal
|
||||
tad swp
|
||||
dac .+1
|
||||
jmp .. i
|
||||
tad u.rq+8 " get address of system call
|
||||
jms laci " load AC indirect??
|
||||
jms betwen; o20001; swn " range check
|
||||
jmp badcal " bad system call
|
||||
tad swp " add system call table base
|
||||
dac .+1 " save as next instruction
|
||||
jmp .. i " dispatch system call
|
||||
|
||||
. = orig+0100
|
||||
jmp coldentry
|
||||
jms halt
|
||||
|
||||
okexit:
|
||||
dzm: u.ac
|
||||
sysexit:
|
||||
ion
|
||||
lac .savblk
|
||||
sza
|
||||
jmp 1f
|
||||
jms copy; sysdata; dskbuf; 64
|
||||
dzm u.ac " 'OK' system call exit: clear user AC
|
||||
sysexit: " common system call exit code
|
||||
ion " enable interrupts
|
||||
lac .savblk " load "save" flag
|
||||
sza " is zero (cleared by disk I/O)?
|
||||
jmp 1f " no: no disk I/O done?
|
||||
jms copy; sysdata; dskbuf; 64 " copy system data to disk buffer
|
||||
cla
|
||||
jms dskio; 07000
|
||||
jms dskio; 07000 " save to disk?
|
||||
1:
|
||||
dzm .insys
|
||||
dzm .insys " clear "in system call" flag
|
||||
jms chkint
|
||||
skp
|
||||
jmp .save
|
||||
jms copy; u.rq+2; 10; 6
|
||||
lac u.rq+1
|
||||
jmp .save " dump core??
|
||||
jms copy; u.rq+2; 10; 6 " restore auto-index locations 10-15
|
||||
lac u.rq+1 " restore auto-index location 9
|
||||
dac 9
|
||||
lac u.rq
|
||||
lac u.rq " restore auto-index location 8
|
||||
dac 8
|
||||
lac u.rq
|
||||
lac u.mq " restore MQ register
|
||||
lmq
|
||||
lac u.ac
|
||||
jmp u.rq+8 i
|
||||
lac u.ac " restore AC register
|
||||
jmp u.rq+8 i " return to user
|
||||
|
||||
swap: 0
|
||||
ion
|
||||
@@ -129,21 +129,21 @@ swap: 0
|
||||
jmp swap i
|
||||
t = t+1
|
||||
|
||||
swp:
|
||||
jmp .
|
||||
swp: " system call dispatch table
|
||||
jmp . " base instruction
|
||||
.save; .getuid; .open; .read; .write; .creat; .seek; .tell
|
||||
.close; .link; .unlink; .setuid; .rename; .exit; .time; .intrp
|
||||
.chdir; .chmod; .chown; badcal; .sysloc; badcal; .capt; .rele
|
||||
.status; badcal; .smes; .rmes; .fork
|
||||
swn:
|
||||
.-swp-1 i
|
||||
.-swp-1 i " count of system calls, plus indirect!
|
||||
|
||||
.intrp:
|
||||
lac u.ac
|
||||
dac u.intflg
|
||||
jmp okexit
|
||||
|
||||
.sysloc:
|
||||
.sysloc: " "sysloc": syscall to return system addresses
|
||||
lac u.ac
|
||||
and o17777
|
||||
jms betwen; d1; locn
|
||||
@@ -154,7 +154,7 @@ swn:
|
||||
dac u.ac
|
||||
jmp sysexit
|
||||
|
||||
locsw:
|
||||
locsw: " table of system data structures for "sysloc" call
|
||||
lac .
|
||||
iget; inode; userdata; sysdata; copy; copyz; betwen; dskrd
|
||||
dskwr; dskbuf; dpdata; namei; pbsflgs; alloc; free; dspdata
|
||||
|
||||
27
src/sys/s2.s
27
src/sys/s2.s
@@ -53,9 +53,9 @@
|
||||
jms iput
|
||||
jmp okexit
|
||||
|
||||
.getuid:
|
||||
.getuid: " getuid system call
|
||||
lac u.uid
|
||||
dac u.ac
|
||||
dac u.ac " return u.uid in user AC
|
||||
jmp sysexit
|
||||
|
||||
.seek:
|
||||
@@ -146,12 +146,12 @@
|
||||
jms iput
|
||||
jmp sysexit
|
||||
|
||||
.setuid:
|
||||
lac u.uid
|
||||
sma
|
||||
jms error
|
||||
lac u.ac
|
||||
dac u.uid
|
||||
.setuid: " setuid system call
|
||||
lac u.uid " load current user id
|
||||
sma " negative?
|
||||
jms error " no: error!!
|
||||
lac u.ac " load user AC
|
||||
dac u.uid " save as new uid
|
||||
jmp sysexit
|
||||
|
||||
.rename:
|
||||
@@ -168,11 +168,14 @@
|
||||
jms copy; 1:0; d.name; 4
|
||||
jmp okexit
|
||||
|
||||
" time system call returns line (mains) frequency ticks since boot?
|
||||
" note: returns uptime!?
|
||||
" at 60Hz, 36 bits would last 36+ years!
|
||||
.time:
|
||||
lac s.tim
|
||||
dac u.ac
|
||||
lac s.tim+1
|
||||
dac u.mq
|
||||
lac s.tim " load high order bits
|
||||
dac u.ac " return in AC
|
||||
lac s.tim+1 " load low order bits
|
||||
dac u.mq " return in MQ
|
||||
jmp sysexit
|
||||
|
||||
.chdir:
|
||||
|
||||
18
src/sys/s7.s
18
src/sys/s7.s
@@ -1,7 +1,7 @@
|
||||
"** 01-s1.pdf page 41
|
||||
" s7
|
||||
|
||||
pibreak:
|
||||
pibreak: " priority interrupt processing "chain"
|
||||
dac .ac "** CROSSED OUT....
|
||||
|
||||
dpsf
|
||||
@@ -25,15 +25,15 @@ pibreak:
|
||||
dac dpwrite
|
||||
jmp piret "** END OF CROSSOUT
|
||||
|
||||
1: clsf
|
||||
jmp 1f
|
||||
1: clsf " clock overflow (line frequency ticks)?
|
||||
jmp 1f " no
|
||||
|
||||
lpb
|
||||
dac pbsflgs
|
||||
isz s.tim+1
|
||||
skp
|
||||
isz s.tim
|
||||
isz uquant
|
||||
lpb " load display push buttons
|
||||
dac pbsflgs " save
|
||||
isz s.tim+1 " increment low order tick count
|
||||
skp " no overflow, skip second increment
|
||||
isz s.tim " low order overflowed, increment high order count
|
||||
isz uquant " increment user quantum counter
|
||||
"** written: ttydelay -> ttyd1
|
||||
"** written: ttyrestart -> ttyres1
|
||||
cnop:
|
||||
|
||||
180
src/sys/sop.s
180
src/sys/sop.s
@@ -1,97 +1,95 @@
|
||||
"** 01-s1.pdf page 62
|
||||
" sop
|
||||
|
||||
dac = 0040000
|
||||
jms = 0100000
|
||||
dzm = 0140000
|
||||
lac = 0200000
|
||||
xor = 0240000
|
||||
add = 0300000
|
||||
tad = 0340000
|
||||
xct = 0400000
|
||||
isz = 0440000
|
||||
and = 0500000
|
||||
sad = 0540000
|
||||
jmp = 0600000
|
||||
nop = 0740000
|
||||
i = 020000
|
||||
law = 0760000
|
||||
cma = 0740001
|
||||
las = 0750004
|
||||
ral = 0740010
|
||||
rar = 0740020
|
||||
hlt = 0740040
|
||||
sma = 0740100
|
||||
sza = 0740200
|
||||
snl = 0740400
|
||||
skp = 0741000
|
||||
sna = 0741200
|
||||
szl = 0741400
|
||||
rtl = 0742010
|
||||
rtr = 0742020
|
||||
cil = 0744000
|
||||
rcl = 0744010
|
||||
rcr = 0744020
|
||||
cia = 0750000
|
||||
lrs = 0640500
|
||||
lrss = 0660500
|
||||
lls = 0640600
|
||||
llss = 0660600
|
||||
als = 0640700
|
||||
alss = 0660700
|
||||
mul = 0653323
|
||||
idiv = 0653323
|
||||
lacq = 0641002
|
||||
clq = 0650000
|
||||
omq = 0650002
|
||||
cmq = 0650004
|
||||
lmq = 0652000
|
||||
dac = 0040000 " MEM: deposit AC
|
||||
jms = 0100000 " MEM: jump to subroutine
|
||||
dzm = 0140000 " MEM: deposit zero to memory
|
||||
lac = 0200000 " MEM: load AC
|
||||
xor = 0240000 " MEM: XOR with AC
|
||||
add = 0300000 " MEM: one's complement add
|
||||
tad = 0340000 " MEM: two's complement add
|
||||
xct = 0400000 " MEM: execute
|
||||
isz = 0440000 " MEM: increment and skip if zero
|
||||
and = 0500000 " MEM: AND
|
||||
sad = 0540000 " MEM: skip if AC different
|
||||
jmp = 0600000 " MEM: jump
|
||||
nop = 0740000 " OPR: no-op
|
||||
i = 020000 " indirect
|
||||
law = 0760000 " OPR: load accumulator with (instr)
|
||||
cma = 0740001 " OPR: complement AC
|
||||
las = 0750004 " OPR: load AC from switches
|
||||
ral = 0740010 " OPR: rotate AC left
|
||||
rar = 0740020 " OPR: rotate AC right
|
||||
hlt = 0740040 " OPR: halt
|
||||
sma = 0740100 " OPR: skip on minus AC
|
||||
sza = 0740200 " OPR: skip on zero AC
|
||||
snl = 0740400 " OPR: skip on non-zero link
|
||||
skp = 0741000 " OPR: skip unconditionally
|
||||
sna = 0741200 " OPR: skip on negative AC
|
||||
szl = 0741400 " OPR: skip on zero link
|
||||
rtl = 0742010 " OPR: rotate two left
|
||||
rtr = 0742020 " OPR: rotate two right
|
||||
cll = 0744000 " OPR: clear link
|
||||
rcl = 0744010 " OPR: clear link, rotate left
|
||||
rcr = 0744020 " OPR: clear link, rotate right
|
||||
cla = 0750000 " OPR: clear AC
|
||||
lrs = 0640500 " EAE: long right shift
|
||||
lrss = 0660500 " EAE: long right shift, signed
|
||||
lls = 0640600 " EAE: long left shift
|
||||
llss = 0660600 " EAE: long left shift, signed
|
||||
als = 0640700 " EAE: AC left shift
|
||||
alss = 0660700 " EAE: AC left shift, signed
|
||||
mul = 0653323 " EAE: multiply
|
||||
idiv = 0653323 " EAE: integer divide
|
||||
lacq = 0641002 " EAE: load AC with MQ
|
||||
clq = 0650000 " EAE: clear MQ
|
||||
omq = 0650002 " EAE: OR MQ into AC
|
||||
cmq = 0650004 " EAE: complement MQ
|
||||
lmq = 0652000 " EAE: load MQ from AC
|
||||
|
||||
dscs = 0707141
|
||||
dslw = 0707124
|
||||
dslm = 0707142
|
||||
dsld = 0707104
|
||||
dsls = 0707144
|
||||
dssf = 0707121
|
||||
dsrs = 0707132
|
||||
|
||||
iof = 0700002
|
||||
ion = 0700042
|
||||
caf = 0703302
|
||||
clon = 0700044
|
||||
clsf = 0700001
|
||||
dscs = 0707141 " DSK: clear status register
|
||||
dslw = 0707124 " DSK: clear and load WC from AC
|
||||
dslm = 0707142 " DSK: clear and load MAC from AC
|
||||
dsld = 0707104 " DSK: clear and load TA and SA from AC
|
||||
dsls = 0707144 " DSK: load status
|
||||
dssf = 0707121 " DSK: skip on flags
|
||||
dsrs = 0707132 " DSK: read status register
|
||||
|
||||
iof = 0700002 " PIC: interrupts off
|
||||
ion = 0700042 " PIC: interrupts on
|
||||
caf = 0703302 " CPU: clear all flags
|
||||
clon = 0700044 " CLK: clear flag, enable
|
||||
clsf = 0700001 " CLK: skip if overflow
|
||||
"** 01-s1.pdf page 63
|
||||
clof = 0700004
|
||||
ksf = 0700301
|
||||
krb = 0700312
|
||||
tsf = 0700401
|
||||
tcf = 0700402
|
||||
tls = 0700406
|
||||
sck = 0704301
|
||||
cck = 0704304
|
||||
lck = 0704312
|
||||
rsf = 0700101
|
||||
rsa = 0700104
|
||||
rrb = 0700112
|
||||
psf = 0700201
|
||||
pcf = 0700202
|
||||
psa = 0700204
|
||||
cdf = 0700501
|
||||
lds = 0701052
|
||||
lda = 0701012
|
||||
wcga = 0704206
|
||||
raef = 0700742
|
||||
rlpd = 0700723
|
||||
beg = 0700547
|
||||
spb = 0704401
|
||||
cpb = 0704404
|
||||
lpb = 0704412
|
||||
wbl = 0704424
|
||||
dprs = 0704752
|
||||
dpsf = 0704741
|
||||
dpcf = 0704761
|
||||
dprc = 0704712
|
||||
crsf = 0706701
|
||||
crrb = 0706712
|
||||
|
||||
clof = 0700004 " CLK: clear flag, disable
|
||||
ksf = 0700301 " KBD: skip if flag set
|
||||
krb = 0700312 " KBD: read buffer
|
||||
tsf = 0700401 " TTY: skip if flag set
|
||||
tcf = 0700402 " TTY: clear flag
|
||||
tls = 0700406 " TTY: load buffer, select
|
||||
sck = 0704301 " S-2: skip on console keyboard
|
||||
cck = 0704304 " S-2: clear console keyboard
|
||||
lck = 0704312 " S-2: load console keyboard
|
||||
rsf = 0700101 " PTR: skip if flag set
|
||||
rsa = 0700104 " PTR: select alphanumeric mode
|
||||
rrb = 0700112 " PTR: clear flag, or read buffer
|
||||
psf = 0700201 " PTP: skip if flag set
|
||||
pcf = 0700202 " PTP: clear flag
|
||||
psa = 0700204 " PTP: alphanumeric mode
|
||||
cdf = 0700501 " ???
|
||||
lds = 0701052 " S-2: load display status
|
||||
lda = 0701012 " S-2: load display address
|
||||
wcga = 0704206 " S-2: ???
|
||||
raef = 0700742 " S-2: resume after edges flag
|
||||
rlpd = 0700723 " S-2: resume after light pen stop, disabled
|
||||
beg = 0700547 " S-2: begin
|
||||
spb = 0704401 " S-2: skip on push button flag
|
||||
cpb = 0704404 " S-2: clear push button flag
|
||||
lpb = 0704412 " S-2: load push buttons
|
||||
wbl = 0704424 " S-2: write button lights
|
||||
dprs = 0704752 " dataphone: read status
|
||||
dpsf = 0704741 " dataphone: skip on flag
|
||||
dpcf = 0704761 " dataphone: clear flag
|
||||
dprc = 0704712 " dataphone: read character
|
||||
crsf = 0706701 " CDR: skip if ready
|
||||
crrb = 0706712 " CDR: read buffer
|
||||
|
||||
125
tools/as7
125
tools/as7
@@ -4,7 +4,7 @@
|
||||
# and convert them into PDP-7 machine code
|
||||
#
|
||||
# (c) 2016 Warren Toomey, GPL3
|
||||
# Tweaked by Phil Budne (expression parsing, "list" format)
|
||||
# Tweaked by Phil Budne (line, expression parsing, "list" format)
|
||||
#
|
||||
use strict;
|
||||
use warnings;
|
||||
@@ -25,7 +25,6 @@ my $origline; # The original current input line of code
|
||||
my $line; # line being parsed
|
||||
my $stage = 1; # Pass one or pass two
|
||||
my $errors = 0; # set to non-zero on error
|
||||
my %Undef; # undefined symbols: only complain once
|
||||
my $line_error = ' ';
|
||||
my $file; # current file name
|
||||
my $lineno; # current line number
|
||||
@@ -149,7 +148,7 @@ usage() if ( @ARGV < 1 );
|
||||
rsb => 0700144, # select PTR in binary mode
|
||||
|
||||
psf => 0700201, # skip if PTP flag set
|
||||
pcf => 0700202, # clear PTP clag
|
||||
pcf => 0700202, # clear PTP flag
|
||||
psa => 0700204, # punch PTP in alphanumeric mode
|
||||
psb => 0700244, # punch PTP in binary mode
|
||||
|
||||
@@ -157,7 +156,7 @@ usage() if ( @ARGV < 1 );
|
||||
krb => 0700312, # read KBD buffer
|
||||
iors => 0700314, # input/output read status
|
||||
|
||||
tsf => 0700401, # if if TTY output flag set
|
||||
tsf => 0700401, # skip if if TTY output flag set
|
||||
tcf => 0700402, # clear TTY output flag
|
||||
tls => 0700406, # load TTY output buffer and select
|
||||
|
||||
@@ -272,8 +271,9 @@ sub parse_file {
|
||||
close($IN);
|
||||
}
|
||||
|
||||
# process a label and set its value to the location counter (only called on pass 1)
|
||||
# (if called on pass 2, should check if values are identical)
|
||||
# process a label and set its value to the location counter
|
||||
# only called on pass 1;
|
||||
# if called on pass 2, should check if values are identical
|
||||
sub process_label {
|
||||
my $label = shift;
|
||||
|
||||
@@ -294,25 +294,21 @@ sub process_label {
|
||||
}
|
||||
|
||||
# Blame Phil for this....
|
||||
# parses global $line based on prefixes
|
||||
# (nibbling of a bit at a time)
|
||||
# parses global $line based on prefixes, nibbling of a bit at a time
|
||||
# (: and ; can appear in char literals)
|
||||
# handles multiple ';' separated words per line
|
||||
sub parse_line {
|
||||
$line_error = ' ';
|
||||
|
||||
# Lose any leading whitespace
|
||||
$line =~ s{^\s*}{};
|
||||
|
||||
while (1) {
|
||||
# Lose any leading whitespace
|
||||
$line =~ s{^\s*}{};
|
||||
$line_error = ' '; # clear listing error indicator
|
||||
|
||||
return if ($line eq '' || $line =~ m{^"}); # empty or comment: quit
|
||||
|
||||
print "parse_line: '$line'\n" if ($debug);
|
||||
|
||||
return if ($line eq '');
|
||||
|
||||
if ($line =~ m{^"}) { # remainder of line is comment
|
||||
return;
|
||||
}
|
||||
|
||||
if ($line =~ s{^([a-z0-9\.]+):}{}) { # label
|
||||
while ($line =~ s{^([a-z0-9\.]+):\s*}{}) { # labels
|
||||
my $label = $1;
|
||||
|
||||
# First pass: parse the labels
|
||||
@@ -321,44 +317,40 @@ sub parse_line {
|
||||
process_label($1);
|
||||
}
|
||||
}
|
||||
else {
|
||||
my $lhs = undef;
|
||||
if ( $line =~ s{^(\S+)\s*=}{}) { # assignment
|
||||
$lhs = $1;
|
||||
}
|
||||
|
||||
if ( $line =~ s{^(\S+)\s*=}{}) { # assignment
|
||||
my $lhs = $1;
|
||||
my $word = parse_expression();
|
||||
if ($lhs) {
|
||||
printf( "Setting variable %s to 0%o\n", $lhs, $word ) if ($debug);
|
||||
$Var{$lhs} = $word;
|
||||
printf("\t%06o %s\n", $word, $line_error) if ($stage == 2 && $format eq 'list');
|
||||
}
|
||||
else { # bare expression
|
||||
# Get its value on pass two and save to memory
|
||||
# Also save the input line that altered memory
|
||||
if ( $stage == 2 ) {
|
||||
my $location = $Var{'.'};
|
||||
$Mem[$location] = $word;
|
||||
$Mline[$location] = $origline;
|
||||
$origline = '';
|
||||
if ($format eq 'list') {
|
||||
printf( "%06o: %06o %s\n", $location, $word, $line_error);
|
||||
}
|
||||
printf( "Setting variable %s to 0%o\n", $lhs, $word ) if ($debug);
|
||||
$Var{$lhs} = $word;
|
||||
printf("\t%06o %s\n", $word, $line_error) if ($stage == 2 && $format eq 'list');
|
||||
}
|
||||
else { # bare expression
|
||||
# Get its value on pass two and save to memory
|
||||
# Also save the input line that altered memory
|
||||
my $word = parse_expression();
|
||||
if ( $stage == 2 ) {
|
||||
my $location = $Var{'.'};
|
||||
$Mem[$location] = $word;
|
||||
$Mline[$location] = $origline;
|
||||
$origline = '';
|
||||
if ($format eq 'list') {
|
||||
printf( "%06o: %06o %s\n", $location, $word, $line_error);
|
||||
}
|
||||
# Move up to the next location in both passes
|
||||
$Var{'.'}++;
|
||||
} # expr
|
||||
} # assignment or expression
|
||||
}
|
||||
# Move up to the next location in both passes
|
||||
$Var{'.'}++;
|
||||
} # expr
|
||||
|
||||
# eat trailing whitespace and ";", if any
|
||||
$line =~ s{^\s*}{};
|
||||
$line =~ s{^;}{};
|
||||
$line =~ s{^\s*;?}{};
|
||||
} # while
|
||||
}
|
||||
|
||||
# Blame Phil for this bit too...
|
||||
# Parse an expression off $line and return a PDP-7 word
|
||||
# as a series of whitespace separated "syllables"
|
||||
# and adds them together.
|
||||
# ORed, added, or subtracted
|
||||
sub parse_expression {
|
||||
my $word = 0;
|
||||
|
||||
@@ -366,23 +358,22 @@ sub parse_expression {
|
||||
|
||||
while (1) {
|
||||
my $syllable = 0;
|
||||
my $sign = 1;
|
||||
my $op = '|';
|
||||
|
||||
$line =~ s{^\s+}{};
|
||||
print " '$line'\n" if ($debug);
|
||||
|
||||
if ($line eq '' || $line =~ m{^[";]}) { # EOL ; and " terminate expr
|
||||
printf("\tparse_expression => %#o\n", $word) if ($debug);
|
||||
return $word;
|
||||
}
|
||||
|
||||
print " '$line'\n" if ($debug);
|
||||
|
||||
if ($line =~ s{^-}{}) {
|
||||
# leading '-' negates upcomming syllable.
|
||||
$sign = -$sign;
|
||||
$op = '-';
|
||||
}
|
||||
else {
|
||||
# ignore leading '+'
|
||||
$line =~ s{^\+}{};
|
||||
elsif ($line =~ s{^\+}{}) {
|
||||
$op = '+';
|
||||
}
|
||||
|
||||
if ($line =~ s{^<(.)}{}) { # <char
|
||||
@@ -406,8 +397,7 @@ sub parse_expression {
|
||||
printf("\tlbl: %s: %#o\n", $sym, $syllable) if ($debug);
|
||||
}
|
||||
elsif ($stage == 2) {
|
||||
err('U', "$sym not defined") unless (defined $Undef{$sym});
|
||||
$Undef{$sym} = 1; # only complain once
|
||||
err('U', "$sym not defined")
|
||||
} # pass 2
|
||||
} # symbol
|
||||
elsif ( $line =~ s{^(\d+)([fb])}{} ) { # relative label
|
||||
@@ -421,14 +411,31 @@ sub parse_expression {
|
||||
else {
|
||||
$syllable = $value + 0;
|
||||
}
|
||||
$syllable &= 0777777;
|
||||
}
|
||||
else {
|
||||
# From the BSD fortune file:
|
||||
# Ken Thompson has an automobile which he helped design.
|
||||
# Unlike most automobiles, it has neither speedometer,
|
||||
# nor gas gauge, nor any of the numerous idiot lights
|
||||
# which plague the modern driver. Rather, if the driver
|
||||
# makes any mistake, a giant "?" lights up in the center
|
||||
# of the dashboard. "The experienced driver",
|
||||
# he says, "will usually know what's wrong.
|
||||
err('?', "huh? '$line'");
|
||||
$line = '';
|
||||
$line = ''; # abort processing
|
||||
return $word;
|
||||
}
|
||||
$syllable = ($syllable * $sign) & 0777777;
|
||||
$word = ($word + $syllable) & 0777777;
|
||||
if ($op eq '+') {
|
||||
$word += $syllable;
|
||||
}
|
||||
elsif ($op eq '-') {
|
||||
$word -= $syllable;
|
||||
}
|
||||
else {
|
||||
$word |= $syllable;
|
||||
}
|
||||
$word &= 0777777;
|
||||
printf("\tsyllable: %#o word: %#o\n", $syllable, $word) if ($debug);
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user