factor/extra/cpu/8080/emulator/emulator.factor

1407 lines
40 KiB
Factor

! Copyright (C) 2006 Chris Double.
! See http://factorcode.org/license.txt for BSD license.
!
USING:
accessors
arrays
assocs
combinators
fry
io
io.encodings.binary
io.files
io.pathnames
kernel
lexer
make
math
math.parser
namespaces
parser
peg
peg.ebnf
peg.parsers
quotations
sequences
sequences.deep
words
;
IN: cpu.8080.emulator
TUPLE: cpu b c d e f h l a pc sp halted? last-interrupt cycles ram ;
GENERIC: reset ( cpu -- )
GENERIC: update-video ( value addr cpu -- )
GENERIC: read-port ( port cpu -- byte )
GENERIC: write-port ( value port cpu -- )
M: cpu update-video ( value addr cpu -- )
3drop ;
M: cpu read-port ( port cpu -- byte )
#! Read a byte from the hardware port. 'port' should
#! be an 8-bit value.
2drop 0 ;
M: cpu write-port ( value port cpu -- )
#! Write a byte to the hardware port, where 'port' is
#! an 8-bit value.
3drop ;
CONSTANT: carry-flag HEX: 01
CONSTANT: parity-flag HEX: 04
CONSTANT: half-carry-flag HEX: 10
CONSTANT: interrupt-flag HEX: 20
CONSTANT: zero-flag HEX: 40
CONSTANT: sign-flag HEX: 80
: >word< ( word -- byte byte )
#! Explode a word into its two 8 bit values.
dup HEX: FF bitand swap -8 shift HEX: FF bitand swap ;
: af>> ( cpu -- word )
#! Return the 16-bit pseudo register AF.
[ a>> 8 shift ] keep f>> bitor ;
: af<< ( value cpu -- )
#! Set the value of the 16-bit pseudo register AF
[ >word< ] dip swap >>f swap >>a drop ;
: bc>> ( cpu -- word )
#! Return the 16-bit pseudo register BC.
[ b>> 8 shift ] keep c>> bitor ;
: bc<< ( value cpu -- )
#! Set the value of the 16-bit pseudo register BC
[ >word< ] dip swap >>c swap >>b drop ;
: de>> ( cpu -- word )
#! Return the 16-bit pseudo register DE.
[ d>> 8 shift ] keep e>> bitor ;
: de<< ( value cpu -- )
#! Set the value of the 16-bit pseudo register DE
[ >word< ] dip swap >>e swap >>d drop ;
: hl>> ( cpu -- word )
#! Return the 16-bit pseudo register HL.
[ h>> 8 shift ] keep l>> bitor ;
: hl<< ( value cpu -- )
#! Set the value of the 16-bit pseudo register HL
[ >word< ] dip swap >>l swap >>h drop ;
: flag-set? ( flag cpu -- bool )
f>> bitand 0 = not ;
: flag-clear? ( flag cpu -- bool )
f>> bitand 0 = ;
: flag-nz? ( cpu -- bool )
#! Test flag status
f>> zero-flag bitand 0 = ;
: flag-z? ( cpu -- bool )
#! Test flag status
f>> zero-flag bitand 0 = not ;
: flag-nc? ( cpu -- bool )
#! Test flag status
f>> carry-flag bitand 0 = ;
: flag-c? ( cpu -- bool )
#! Test flag status
f>> carry-flag bitand 0 = not ;
: flag-po? ( cpu -- bool )
#! Test flag status
f>> parity-flag bitand 0 = ;
: flag-pe? ( cpu -- bool )
#! Test flag status
f>> parity-flag bitand 0 = not ;
: flag-p? ( cpu -- bool )
#! Test flag status
f>> sign-flag bitand 0 = ;
: flag-m? ( cpu -- bool )
#! Test flag status
f>> sign-flag bitand 0 = not ;
: read-byte ( addr cpu -- byte )
#! Read one byte from memory at the specified address.
#! The address is 16-bit, but if a value greater than
#! 0xFFFF is provided then return a default value.
over HEX: FFFF <= [
ram>> nth
] [
2drop HEX: FF
] if ;
: read-word ( addr cpu -- word )
#! Read a 16-bit word from memory at the specified address.
#! The address is 16-bit, but if a value greater than
#! 0xFFFF is provided then return a default value.
[ read-byte ] 2keep [ 1 + ] dip read-byte 8 shift bitor ;
: next-byte ( cpu -- byte )
#! Return the value of the byte at PC, and increment PC.
[ pc>> ] keep
[ read-byte ] keep
[ pc>> 1 + ] keep
pc<< ;
: next-word ( cpu -- word )
#! Return the value of the word at PC, and increment PC.
[ pc>> ] keep
[ read-word ] keep
[ pc>> 2 + ] keep
pc<< ;
: write-byte ( value addr cpu -- )
#! Write a byte to the specified memory address.
over dup HEX: 2000 < swap HEX: FFFF > or [
3drop
] [
3dup ram>> set-nth
update-video
] if ;
: write-word ( value addr cpu -- )
#! Write a 16-bit word to the specified memory address.
[ >word< ] 2dip [ write-byte ] 2keep [ 1 + ] dip write-byte ;
: cpu-a-bitand ( quot cpu -- )
#! A &= quot call
[ a>> swap call bitand ] keep a<< ; inline
: cpu-a-bitor ( quot cpu -- )
#! A |= quot call
[ a>> swap call bitor ] keep a<< ; inline
: cpu-a-bitxor ( quot cpu -- )
#! A ^= quot call
[ a>> swap call bitxor ] keep a<< ; inline
: cpu-a-bitxor= ( value cpu -- )
#! cpu-a ^= value
[ a>> bitxor ] keep a<< ;
: cpu-f-bitand ( quot cpu -- )
#! F &= quot call
[ f>> swap call bitand ] keep f<< ; inline
: cpu-f-bitor ( quot cpu -- )
#! F |= quot call
[ f>> swap call bitor ] keep f<< ; inline
: cpu-f-bitxor ( quot cpu -- )
#! F |= quot call
[ f>> swap call bitxor ] keep f<< ; inline
: cpu-f-bitor= ( value cpu -- )
#! cpu-f |= value
[ f>> bitor ] keep f<< ;
: cpu-f-bitand= ( value cpu -- )
#! cpu-f &= value
[ f>> bitand ] keep f<< ;
: cpu-f-bitxor= ( value cpu -- )
#! cpu-f ^= value
[ f>> bitxor ] keep f<< ;
: set-flag ( cpu flag -- )
swap cpu-f-bitor= ;
: clear-flag ( cpu flag -- )
bitnot HEX: FF bitand swap cpu-f-bitand= ;
: update-zero-flag ( result cpu -- )
#! If the result of an instruction has the value 0, this
#! flag is set, otherwise it is reset.
swap HEX: FF bitand 0 = [ zero-flag set-flag ] [ zero-flag clear-flag ] if ;
: update-sign-flag ( result cpu -- )
#! If the most significant bit of the result
#! has the value 1 then the flag is set, otherwise
#! it is reset.
swap HEX: 80 bitand 0 = [ sign-flag clear-flag ] [ sign-flag set-flag ] if ;
: update-parity-flag ( result cpu -- )
#! If the modulo 2 sum of the bits of the result
#! is 0, (ie. if the result has even parity) this flag
#! is set, otherwise it is reset.
swap HEX: FF bitand 2 mod 0 = [ parity-flag set-flag ] [ parity-flag clear-flag ] if ;
: update-carry-flag ( result cpu -- )
#! If the instruction resulted in a carry (from addition)
#! or a borrow (from subtraction or a comparison) out of the
#! higher order bit, this flag is set, otherwise it is reset.
swap dup HEX: 100 >= swap 0 < or [ carry-flag set-flag ] [ carry-flag clear-flag ] if ;
: update-half-carry-flag ( original change-by result cpu -- )
#! If the instruction caused a carry out of bit 3 and into bit 4 of the
#! resulting value, the half carry flag is set, otherwise it is reset.
#! The 'original' is the original value of the register being changed.
#! 'change-by' is the amount it is being added or decremented by.
#! 'result' is the result of that change.
[ bitxor bitxor HEX: 10 bitand 0 = not ] dip
swap [ half-carry-flag set-flag ] [ half-carry-flag clear-flag ] if ;
: update-flags ( result cpu -- )
2dup update-carry-flag
2dup update-parity-flag
2dup update-sign-flag
update-zero-flag ;
: update-flags-no-carry ( result cpu -- )
2dup update-parity-flag
2dup update-sign-flag
update-zero-flag ;
: add-byte ( lhs rhs cpu -- result )
#! Add rhs to lhs
[ 2dup + ] dip
[ update-flags ] 2keep
[ update-half-carry-flag ] 2keep
drop HEX: FF bitand ;
: add-carry ( change-by result cpu -- change-by result )
#! Add the effect of the carry flag to the result
flag-c? [ 1 + [ 1 + ] dip ] when ;
: add-byte-with-carry ( lhs rhs cpu -- result )
#! Add rhs to lhs plus carry.
[ 2dup + ] dip
[ add-carry ] keep
[ update-flags ] 2keep
[ update-half-carry-flag ] 2keep
drop HEX: FF bitand ;
: sub-carry ( change-by result cpu -- change-by result )
#! Subtract the effect of the carry flag from the result
flag-c? [ 1 - [ 1 - ] dip ] when ;
: sub-byte ( lhs rhs cpu -- result )
#! Subtract rhs from lhs
[ 2dup - ] dip
[ update-flags ] 2keep
[ update-half-carry-flag ] 2keep
drop HEX: FF bitand ;
: sub-byte-with-carry ( lhs rhs cpu -- result )
#! Subtract rhs from lhs and take carry into account
[ 2dup - ] dip
[ sub-carry ] keep
[ update-flags ] 2keep
[ update-half-carry-flag ] 2keep
drop HEX: FF bitand ;
: inc-byte ( byte cpu -- result )
#! Increment byte by one. Note that carry flag is not affected
#! by this operation.
[ 1 2dup + ] dip
[ update-flags-no-carry ] 2keep
[ update-half-carry-flag ] 2keep
drop HEX: FF bitand ;
: dec-byte ( byte cpu -- result )
#! Decrement byte by one. Note that carry flag is not affected
#! by this operation.
[ 1 2dup - ] dip
[ update-flags-no-carry ] 2keep
[ update-half-carry-flag ] 2keep
drop HEX: FF bitand ;
: inc-word ( w cpu -- w )
#! Increment word by one. Note that no flags are modified.
drop 1 + HEX: FFFF bitand ;
: dec-word ( w cpu -- w )
#! Decrement word by one. Note that no flags are modified.
drop 1 - HEX: FFFF bitand ;
: add-word ( lhs rhs cpu -- result )
#! Add rhs to lhs. Note that only the carry flag is modified
#! and only if there is a carry out of the double precision add.
[ + ] dip over HEX: FFFF > [ carry-flag set-flag ] [ drop ] if HEX: FFFF bitand ;
: bit3or ( lhs rhs -- 0|1 )
#! bitor bit 3 of the two numbers on the stack
BIN: 00001000 bitand -3 shift [
BIN: 00001000 bitand -3 shift
] dip
bitor ;
: and-byte ( lhs rhs cpu -- result )
#! Logically and rhs to lhs. The carry flag is cleared and
#! the half carry is set to the ORing of bits 3 of the operands.
[ drop bit3or ] 3keep ! bit3or lhs rhs cpu
[ bitand ] dip [ update-flags ] 2keep
[ carry-flag clear-flag ] keep
rot 0 = [ half-carry-flag set-flag ] [ half-carry-flag clear-flag ] if
HEX: FF bitand ;
: xor-byte ( lhs rhs cpu -- result )
#! Logically xor rhs to lhs. The carry and half-carry flags are cleared.
[ bitxor ] dip [ update-flags ] 2keep
[ half-carry-flag carry-flag bitor clear-flag ] keep
drop HEX: FF bitand ;
: or-byte ( lhs rhs cpu -- result )
#! Logically or rhs to lhs. The carry and half-carry flags are cleared.
[ bitor ] dip [ update-flags ] 2keep
[ half-carry-flag carry-flag bitor clear-flag ] keep
drop HEX: FF bitand ;
: decrement-sp ( n cpu -- )
#! Decrement the stackpointer by n.
[ sp>> ] keep
[ swap - ] dip sp<< ;
: save-pc ( cpu -- )
#! Save the value of the PC on the stack.
[ pc>> ] keep ! pc cpu
[ sp>> ] keep ! pc sp cpu
write-word ;
: push-pc ( cpu -- )
#! Push the value of the PC on the stack.
2 over decrement-sp
save-pc ;
: pop-pc ( cpu -- pc )
#! Pop the value of the PC off the stack.
[ sp>> ] keep
[ read-word ] keep
-2 swap decrement-sp ;
: push-sp ( value cpu -- )
[ 2 swap decrement-sp ] keep
[ sp>> ] keep
write-word ;
: pop-sp ( cpu -- value )
[ sp>> ] keep
[ read-word ] keep
-2 swap decrement-sp ;
: call-sub ( addr cpu -- )
#! Call the address as a subroutine.
dup push-pc
[ HEX: FFFF bitand ] dip pc<< ;
: ret-from-sub ( cpu -- )
[ pop-pc ] keep pc<< ;
: interrupt ( number cpu -- )
#! Perform a hardware interrupt
! "***Interrupt: " write over >hex print
dup f>> interrupt-flag bitand 0 = not [
dup push-pc
pc<<
] [
2drop
] if ;
: inc-cycles ( n cpu -- )
#! Increment the number of cpu cycles
[ cycles>> + ] keep cycles<< ;
: instruction-cycles ( -- vector )
#! Return a 256 element vector containing the cycles for
#! each opcode in the 8080 instruction set.
\ instruction-cycles get-global [
256 f <array> \ instruction-cycles set-global
] unless
\ instruction-cycles get-global ;
: not-implemented ( <cpu> -- )
drop ;
: instructions ( -- vector )
#! Return a 256 element vector containing the emulation words for
#! each opcode in the 8080 instruction set.
\ instructions get-global [
256 [ not-implemented ] <array> \ instructions set-global
] unless
\ instructions get-global ;
: set-instruction ( quot n -- )
instructions set-nth ;
M: cpu reset ( cpu -- )
#! Reset the CPU to its poweron state
0 >>b
0 >>c
0 >>d
0 >>e
0 >>h
0 >>l
0 >>a
0 >>f
0 >>pc
HEX: F000 >>sp
HEX: FFFF 0 <array> >>ram
f >>halted?
HEX: 10 >>last-interrupt
0 >>cycles
drop ;
: <cpu> ( -- cpu ) cpu new dup reset ;
: (load-rom) ( n ram -- )
read1 [ ! n ram ch
-rot [ set-nth ] 2keep [ 1 + ] dip (load-rom)
] [
2drop
] if* ;
#! Reads the ROM from stdin and stores it in ROM from
#! offset n.
: load-rom ( filename cpu -- )
#! Load the contents of the file into ROM.
#! (address 0x0000-0x1FFF).
ram>> swap binary [
0 swap (load-rom)
] with-file-reader ;
SYMBOL: rom-root
: rom-dir ( -- string )
rom-root get [ home "roms" append-path dup exists? [ drop f ] unless ] unless* ;
: load-rom* ( seq cpu -- )
#! 'seq' is an array of arrays. Each array contains
#! an address and filename of a ROM file. The ROM
#! file will be loaded at the specified address. This
#! file path shoul dbe relative to the '/roms' resource path.
rom-dir [
ram>> [
swap first2 rom-dir prepend-path binary [
swap (load-rom)
] with-file-reader
] curry each
] [
!
! the ROM files.
"Set 'rom-root' to the path containing the root of the 8080 ROM files." throw
] if ;
: read-instruction ( cpu -- word )
#! Read the next instruction from the cpu's program
#! counter, and increment the program counter.
[ pc>> ] keep ! pc cpu
[ over 1 + swap pc<< ] keep
read-byte ;
: get-cycles ( n -- opcode )
#! Returns the cycles for the given instruction value.
#! If the opcode is not defined throw an error.
dup instruction-cycles nth [
nip
] [
[ "Undefined 8080 opcode: " % number>string % ] "" make throw
] if* ;
: process-interrupts ( cpu -- )
#! Process any hardware interrupts
[ cycles>> ] keep
over 16667 < [
2drop
] [
[ [ 16667 - ] dip cycles<< ] keep
dup last-interrupt>> HEX: 10 = [
HEX: 08 over last-interrupt<< HEX: 08 swap interrupt
] [
HEX: 10 over last-interrupt<< HEX: 10 swap interrupt
] if
] if ;
: peek-instruction ( cpu -- word )
#! Return the next instruction from the cpu's program
#! counter, but don't increment the counter.
[ pc>> ] keep read-byte instructions nth first ;
: cpu. ( cpu -- )
[ " PC: " write pc>> >hex 4 CHAR: \s pad-head write ] keep
[ " B: " write b>> >hex 2 CHAR: \s pad-head write ] keep
[ " C: " write c>> >hex 2 CHAR: \s pad-head write ] keep
[ " D: " write d>> >hex 2 CHAR: \s pad-head write ] keep
[ " E: " write e>> >hex 2 CHAR: \s pad-head write ] keep
[ " F: " write f>> >hex 2 CHAR: \s pad-head write ] keep
[ " H: " write h>> >hex 2 CHAR: \s pad-head write ] keep
[ " L: " write l>> >hex 2 CHAR: \s pad-head write ] keep
[ " A: " write a>> >hex 2 CHAR: \s pad-head write ] keep
[ " SP: " write sp>> >hex 4 CHAR: \s pad-head write ] keep
[ " cycles: " write cycles>> number>string 5 CHAR: \s pad-head write ] keep
[ " " write peek-instruction name>> write " " write ] keep
nl drop ;
: cpu*. ( cpu -- )
[ " PC: " write pc>> >hex 4 CHAR: \s pad-head write ] keep
[ " B: " write b>> >hex 2 CHAR: \s pad-head write ] keep
[ " C: " write c>> >hex 2 CHAR: \s pad-head write ] keep
[ " D: " write d>> >hex 2 CHAR: \s pad-head write ] keep
[ " E: " write e>> >hex 2 CHAR: \s pad-head write ] keep
[ " F: " write f>> >hex 2 CHAR: \s pad-head write ] keep
[ " H: " write h>> >hex 2 CHAR: \s pad-head write ] keep
[ " L: " write l>> >hex 2 CHAR: \s pad-head write ] keep
[ " A: " write a>> >hex 2 CHAR: \s pad-head write ] keep
[ " SP: " write sp>> >hex 4 CHAR: \s pad-head write ] keep
[ " cycles: " write cycles>> number>string 5 CHAR: \s pad-head write ] keep
nl drop ;
: register-lookup ( string -- vector )
#! Given a string containing a register name, return a vector
#! where the 1st item is the getter and the 2nd is the setter
#! for that register.
H{
{ "A" { a>> a<< } }
{ "B" { b>> b<< } }
{ "C" { c>> c<< } }
{ "D" { d>> d<< } }
{ "E" { e>> e<< } }
{ "H" { h>> h<< } }
{ "L" { l>> l<< } }
{ "AF" { af>> af<< } }
{ "BC" { bc>> bc<< } }
{ "DE" { de>> de<< } }
{ "HL" { hl>> hl<< } }
{ "SP" { sp>> sp<< } }
} at ;
: flag-lookup ( string -- vector )
#! Given a string containing a flag name, return a vector
#! where the 1st item is a word that tests that flag.
H{
{ "NZ" { flag-nz? } }
{ "NC" { flag-nc? } }
{ "PO" { flag-po? } }
{ "PE" { flag-pe? } }
{ "Z" { flag-z? } }
{ "C" { flag-c? } }
{ "P" { flag-p? } }
{ "M" { flag-m? } }
} at ;
SYMBOLS: $1 $2 $3 $4 ;
: replace-patterns ( vector tree -- tree )
[
{
{ $1 [ first ] }
{ $2 [ second ] }
{ $3 [ third ] }
{ $4 [ fourth ] }
[ nip ]
} case
] with deep-map ;
: (emulate-RST) ( n cpu -- )
#! RST nn
[ sp>> 2 - dup ] keep ! sp sp cpu
[ sp<< ] keep ! sp cpu
[ pc>> ] keep ! sp pc cpu
swapd [ write-word ] keep ! cpu
[ 8 * ] dip pc<< ;
: (emulate-CALL) ( cpu -- )
#! 205 - CALL nn
[ next-word HEX: FFFF bitand ] keep ! addr cpu
[ sp>> 2 - dup ] keep ! addr sp sp cpu
[ sp<< ] keep ! addr sp cpu
[ pc>> ] keep ! addr sp pc cpu
swapd [ write-word ] keep ! addr cpu
pc<< ;
: (emulate-RLCA) ( cpu -- )
#! The content of the accumulator is rotated left
#! one position. The low order bit and the carry flag
#! are both set to the value shifd out of the high
#! order bit position. Only the carry flag is affected.
[ a>> -7 shift ] keep
over 0 = [ dup carry-flag clear-flag ] [ dup carry-flag set-flag ] if
[ a>> 1 shift HEX: FF bitand ] keep
[ bitor ] dip a<< ;
: (emulate-RRCA) ( cpu -- )
#! The content of the accumulator is rotated right
#! one position. The high order bit and the carry flag
#! are both set to the value shifd out of the low
#! order bit position. Only the carry flag is affected.
[ a>> 1 bitand 7 shift ] keep
over 0 = [ dup carry-flag clear-flag ] [ dup carry-flag set-flag ] if
[ a>> 254 bitand -1 shift ] keep
[ bitor ] dip a<< ;
: (emulate-RLA) ( cpu -- )
#! The content of the accumulator is rotated left
#! one position through the carry flag. The low
#! order bit is set equal to the carry flag and
#! the carry flag is set to the value shifd out
#! of the high order bit. Only the carry flag is
#! affected.
[ carry-flag swap flag-set? [ 1 ] [ 0 ] if ] keep
[ a>> 127 bitand 7 shift ] keep
dup a>> 128 bitand 0 = [ dup carry-flag clear-flag ] [ dup carry-flag set-flag ] if
[ bitor ] dip a<< ;
: (emulate-RRA) ( cpu -- )
#! The content of the accumulator is rotated right
#! one position through the carry flag. The high order
#! bit is set to the carry flag and the carry flag is
#! set to the value shifd out of the low order bit.
#! Only the carry flag is affected.
[ carry-flag swap flag-set? [ BIN: 10000000 ] [ 0 ] if ] keep
[ a>> 254 bitand -1 shift ] keep
dup a>> 1 bitand 0 = [ dup carry-flag clear-flag ] [ dup carry-flag set-flag ] if
[ bitor ] dip a<< ;
: (emulate-CPL) ( cpu -- )
#! The contents of the accumulator are complemented
#! (zero bits become one, one bits becomes zero).
#! No flags are affected.
HEX: FF swap cpu-a-bitxor= ;
: (emulate-DAA) ( cpu -- )
#! The eight bit number in the accumulator is
#! adjusted to form two four-bit binary-coded-decimal
#! digits.
[
dup half-carry-flag swap flag-set? swap
a>> BIN: 1111 bitand 9 > or [ 6 ] [ 0 ] if
] keep
[ a>> + ] keep
[ update-flags ] 2keep
[ swap HEX: FF bitand swap a<< ] keep
[
dup carry-flag swap flag-set? swap
a>> -4 shift BIN: 1111 bitand 9 > or [ 96 ] [ 0 ] if
] keep
[ a>> + ] keep
[ update-flags ] 2keep
swap HEX: FF bitand swap a<< ;
: patterns ( -- hashtable )
#! table of code quotation patterns for each type of instruction.
H{
{ "NOP" [ drop ] }
{ "RET-NN" [ ret-from-sub ] }
{ "RST-0" [ 0 swap (emulate-RST) ] }
{ "RST-8" [ 8 swap (emulate-RST) ] }
{ "RST-10H" [ HEX: 10 swap (emulate-RST) ] }
{ "RST-18H" [ HEX: 18 swap (emulate-RST) ] }
{ "RST-20H" [ HEX: 20 swap (emulate-RST) ] }
{ "RST-28H" [ HEX: 28 swap (emulate-RST) ] }
{ "RST-30H" [ HEX: 30 swap (emulate-RST) ] }
{ "RST-38H" [ HEX: 38 swap (emulate-RST) ] }
{ "RET-F|FF" [ dup $1 [ 6 over inc-cycles ret-from-sub ] [ drop ] if ] }
{ "CP-N" [ [ a>> ] keep [ next-byte ] keep sub-byte drop ] }
{ "CP-R" [ [ a>> ] keep [ $1 ] keep sub-byte drop ] }
{ "CP-(RR)" [ [ a>> ] keep [ $1 ] keep [ read-byte ] keep sub-byte drop ] }
{ "OR-N" [ [ a>> ] keep [ next-byte ] keep [ or-byte ] keep a<< ] }
{ "OR-R" [ [ a>> ] keep [ $1 ] keep [ or-byte ] keep a<< ] }
{ "OR-(RR)" [ [ a>> ] keep [ $1 ] keep [ read-byte ] keep [ or-byte ] keep a<< ] }
{ "XOR-N" [ [ a>> ] keep [ next-byte ] keep [ xor-byte ] keep a<< ] }
{ "XOR-R" [ [ a>> ] keep [ $1 ] keep [ xor-byte ] keep a<< ] }
{ "XOR-(RR)" [ [ a>> ] keep [ $1 ] keep [ read-byte ] keep [ xor-byte ] keep a<< ] }
{ "AND-N" [ [ a>> ] keep [ next-byte ] keep [ and-byte ] keep a<< ] }
{ "AND-R" [ [ a>> ] keep [ $1 ] keep [ and-byte ] keep a<< ] }
{ "AND-(RR)" [ [ a>> ] keep [ $1 ] keep [ read-byte ] keep [ and-byte ] keep a<< ] }
{ "ADC-R,N" [ [ $1 ] keep [ next-byte ] keep [ add-byte-with-carry ] keep $2 ] }
{ "ADC-R,R" [ [ $1 ] keep [ $3 ] keep [ add-byte-with-carry ] keep $2 ] }
{ "ADC-R,(RR)" [ [ $1 ] keep [ $3 ] keep [ read-byte ] keep [ add-byte-with-carry ] keep $2 ] }
{ "ADD-R,N" [ [ $1 ] keep [ next-byte ] keep [ add-byte ] keep $2 ] }
{ "ADD-R,R" [ [ $1 ] keep [ $3 ] keep [ add-byte ] keep $2 ] }
{ "ADD-RR,RR" [ [ $1 ] keep [ $3 ] keep [ add-word ] keep $2 ] }
{ "ADD-R,(RR)" [ [ $1 ] keep [ $3 ] keep [ read-byte ] keep [ add-byte ] keep $2 ] }
{ "SBC-R,N" [ [ $1 ] keep [ next-byte ] keep [ sub-byte-with-carry ] keep $2 ] }
{ "SBC-R,R" [ [ $1 ] keep [ $3 ] keep [ sub-byte-with-carry ] keep $2 ] }
{ "SBC-R,(RR)" [ [ $1 ] keep [ $3 ] keep [ read-byte ] keep [ sub-byte-with-carry ] keep $2 ] }
{ "SUB-R" [ [ a>> ] keep [ $1 ] keep [ sub-byte ] keep a<< ] }
{ "SUB-(RR)" [ [ a>> ] keep [ $1 ] keep [ read-byte ] keep [ sub-byte ] keep a<< ] }
{ "SUB-N" [ [ a>> ] keep [ next-byte ] keep [ sub-byte ] keep a<< ] }
{ "CPL" [ (emulate-CPL) ] }
{ "DAA" [ (emulate-DAA) ] }
{ "RLA" [ (emulate-RLA) ] }
{ "RRA" [ (emulate-RRA) ] }
{ "CCF" [ carry-flag swap cpu-f-bitxor= ] }
{ "SCF" [ carry-flag swap cpu-f-bitor= ] }
{ "RLCA" [ (emulate-RLCA) ] }
{ "RRCA" [ (emulate-RRCA) ] }
{ "HALT" [ drop ] }
{ "DI" [ [ 255 interrupt-flag - ] swap cpu-f-bitand ] }
{ "EI" [ [ interrupt-flag ] swap cpu-f-bitor ] }
{ "POP-RR" [ [ pop-sp ] keep $2 ] }
{ "PUSH-RR" [ [ $1 ] keep push-sp ] }
{ "INC-R" [ [ $1 ] keep [ inc-byte ] keep $2 ] }
{ "DEC-R" [ [ $1 ] keep [ dec-byte ] keep $2 ] }
{ "INC-RR" [ [ $1 ] keep [ inc-word ] keep $2 ] }
{ "DEC-RR" [ [ $1 ] keep [ dec-word ] keep $2 ] }
{ "DEC-(RR)" [ [ $1 ] keep [ read-byte ] keep [ dec-byte ] keep [ $1 ] keep write-byte ] }
{ "INC-(RR)" [ [ $1 ] keep [ read-byte ] keep [ inc-byte ] keep [ $1 ] keep write-byte ] }
{ "JP-NN" [ [ pc>> ] keep [ read-word ] keep pc<< ] }
{ "JP-F|FF,NN" [ [ $1 ] keep swap [ [ next-word ] keep [ pc<< ] keep [ cycles>> ] keep swap 5 + swap cycles<< ] [ [ pc>> 2 + ] keep pc<< ] if ] }
{ "JP-(RR)" [ [ $1 ] keep pc<< ] }
{ "CALL-NN" [ (emulate-CALL) ] }
{ "CALL-F|FF,NN" [ [ $1 ] keep swap [ 7 over inc-cycles (emulate-CALL) ] [ [ pc>> 2 + ] keep pc<< ] if ] }
{ "LD-RR,NN" [ [ next-word ] keep $2 ] }
{ "LD-RR,RR" [ [ $3 ] keep $2 ] }
{ "LD-R,N" [ [ next-byte ] keep $2 ] }
{ "LD-(RR),N" [ [ next-byte ] keep [ $1 ] keep write-byte ] }
{ "LD-(RR),R" [ [ $3 ] keep [ $1 ] keep write-byte ] }
{ "LD-R,R" [ [ $3 ] keep $2 ] }
{ "LD-R,(RR)" [ [ $3 ] keep [ read-byte ] keep $2 ] }
{ "LD-(NN),RR" [ [ $1 ] keep [ next-word ] keep write-word ] }
{ "LD-(NN),R" [ [ $1 ] keep [ next-word ] keep write-byte ] }
{ "LD-RR,(NN)" [ [ next-word ] keep [ read-word ] keep $2 ] }
{ "LD-R,(NN)" [ [ next-word ] keep [ read-byte ] keep $2 ] }
{ "OUT-(N),R" [ [ $1 ] keep [ next-byte ] keep write-port ] }
{ "IN-R,(N)" [ [ next-byte ] keep [ read-port ] keep a<< ] }
{ "EX-(RR),RR" [ [ $1 ] keep [ read-word ] keep [ $3 ] keep [ $1 ] keep [ write-word ] keep $4 ] }
{ "EX-RR,RR" [ [ $1 ] keep [ $3 ] keep [ $2 ] keep $4 ] }
} ;
: 8-bit-registers ( -- parser )
#! A parser for 8-bit registers. On a successfull parse the
#! parse tree contains a vector. The first item in the vector
#! is the getter word for that register with stack effect
#! ( cpu -- value ). The second item is the setter word with
#! stack effect ( value cpu -- ).
<EBNF
main=("A" | "B" | "C" | "D" | "E" | "H" | "L") => [[ register-lookup ]]
EBNF> ;
: all-flags ( -- parser )
#! A parser for 16-bit flags.
<EBNF
main=("NZ" | "NC" | "PO" | "PE" | "Z" | "C" | "P" | "M") => [[ flag-lookup ]]
EBNF> ;
: 16-bit-registers ( -- parser )
#! A parser for 16-bit registers. On a successfull parse the
#! parse tree contains a vector. The first item in the vector
#! is the getter word for that register with stack effect
#! ( cpu -- value ). The second item is the setter word with
#! stack effect ( value cpu -- ).
<EBNF
main=("AF" | "BC" | "DE" | "HL" | "SP") => [[ register-lookup ]]
EBNF> ;
: all-registers ( -- parser )
#! Return a parser that can parse the format
#! for 8 bit or 16 bit registers.
[ 16-bit-registers , 8-bit-registers , ] choice* ;
: indirect ( parser -- parser )
#! Given a parser, return a parser which parses the original
#! wrapped in brackets, representing an indirect reference.
#! eg. BC -> (BC). The value of the original parser is left in
#! the parse tree.
"(" ")" surrounded-by ;
: generate-instruction ( vector string -- quot )
#! Generate the quotation for an instruction, given the instruction in
#! the 'string' and a vector containing the arguments for that instruction.
patterns at replace-patterns ;
: simple-instruction ( token -- parser )
#! Return a parser for then instruction identified by the token.
#! The parser return parses the token only and expects no additional
#! arguments to the instruction.
token [ '[ { } _ generate-instruction ] ] action ;
: complex-instruction ( type token -- parser )
#! Return a parser for an instruction identified by the token.
#! The instruction is expected to take additional arguments by
#! being combined with other parsers. Then 'type' is used for a lookup
#! in a pattern hashtable to return the instruction quotation pattern.
token swap [ nip '[ _ generate-instruction ] ] curry action ;
: no-params ( ast -- ast )
first { } swap curry ;
: one-param ( ast -- ast )
first2 swap curry ;
: two-params ( ast -- ast )
first3 append swap curry ;
: NOP-instruction ( -- parser )
"NOP" simple-instruction ;
: RET-NN-instruction ( -- parser )
[
"RET-NN" "RET" complex-instruction ,
"nn" token sp hide ,
] seq* [ no-params ] action ;
: RST-0-instruction ( -- parser )
[
"RST-0" "RST" complex-instruction ,
"0" token sp hide ,
] seq* [ no-params ] action ;
: RST-8-instruction ( -- parser )
[
"RST-8" "RST" complex-instruction ,
"8" token sp hide ,
] seq* [ no-params ] action ;
: RST-10H-instruction ( -- parser )
[
"RST-10H" "RST" complex-instruction ,
"10H" token sp hide ,
] seq* [ no-params ] action ;
: RST-18H-instruction ( -- parser )
[
"RST-18H" "RST" complex-instruction ,
"18H" token sp hide ,
] seq* [ no-params ] action ;
: RST-20H-instruction ( -- parser )
[
"RST-20H" "RST" complex-instruction ,
"20H" token sp hide ,
] seq* [ no-params ] action ;
: RST-28H-instruction ( -- parser )
[
"RST-28H" "RST" complex-instruction ,
"28H" token sp hide ,
] seq* [ no-params ] action ;
: RST-30H-instruction ( -- parser )
[
"RST-30H" "RST" complex-instruction ,
"30H" token sp hide ,
] seq* [ no-params ] action ;
: RST-38H-instruction ( -- parser )
[
"RST-38H" "RST" complex-instruction ,
"38H" token sp hide ,
] seq* [ no-params ] action ;
: JP-NN-instruction ( -- parser )
[
"JP-NN" "JP" complex-instruction ,
"nn" token sp hide ,
] seq* [ no-params ] action ;
: JP-F|FF,NN-instruction ( -- parser )
[
"JP-F|FF,NN" "JP" complex-instruction ,
all-flags sp ,
",nn" token hide ,
] seq* [ one-param ] action ;
: JP-(RR)-instruction ( -- parser )
[
"JP-(RR)" "JP" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: CALL-NN-instruction ( -- parser )
[
"CALL-NN" "CALL" complex-instruction ,
"nn" token sp hide ,
] seq* [ no-params ] action ;
: CALL-F|FF,NN-instruction ( -- parser )
[
"CALL-F|FF,NN" "CALL" complex-instruction ,
all-flags sp ,
",nn" token hide ,
] seq* [ one-param ] action ;
: RLCA-instruction ( -- parser )
"RLCA" simple-instruction ;
: RRCA-instruction ( -- parser )
"RRCA" simple-instruction ;
: HALT-instruction ( -- parser )
"HALT" simple-instruction ;
: DI-instruction ( -- parser )
"DI" simple-instruction ;
: EI-instruction ( -- parser )
"EI" simple-instruction ;
: CPL-instruction ( -- parser )
"CPL" simple-instruction ;
: CCF-instruction ( -- parser )
"CCF" simple-instruction ;
: SCF-instruction ( -- parser )
"SCF" simple-instruction ;
: DAA-instruction ( -- parser )
"DAA" simple-instruction ;
: RLA-instruction ( -- parser )
"RLA" simple-instruction ;
: RRA-instruction ( -- parser )
"RRA" simple-instruction ;
: DEC-R-instruction ( -- parser )
[
"DEC-R" "DEC" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: DEC-RR-instruction ( -- parser )
[
"DEC-RR" "DEC" complex-instruction ,
16-bit-registers sp ,
] seq* [ one-param ] action ;
: DEC-(RR)-instruction ( -- parser )
[
"DEC-(RR)" "DEC" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: POP-RR-instruction ( -- parser )
[
"POP-RR" "POP" complex-instruction ,
all-registers sp ,
] seq* [ one-param ] action ;
: PUSH-RR-instruction ( -- parser )
[
"PUSH-RR" "PUSH" complex-instruction ,
all-registers sp ,
] seq* [ one-param ] action ;
: INC-R-instruction ( -- parser )
[
"INC-R" "INC" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: INC-RR-instruction ( -- parser )
[
"INC-RR" "INC" complex-instruction ,
16-bit-registers sp ,
] seq* [ one-param ] action ;
: INC-(RR)-instruction ( -- parser )
[
"INC-(RR)" "INC" complex-instruction ,
all-registers indirect sp ,
] seq* [ one-param ] action ;
: RET-F|FF-instruction ( -- parser )
[
"RET-F|FF" "RET" complex-instruction ,
all-flags sp ,
] seq* [ one-param ] action ;
: AND-N-instruction ( -- parser )
[
"AND-N" "AND" complex-instruction ,
"n" token sp hide ,
] seq* [ no-params ] action ;
: AND-R-instruction ( -- parser )
[
"AND-R" "AND" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: AND-(RR)-instruction ( -- parser )
[
"AND-(RR)" "AND" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: XOR-N-instruction ( -- parser )
[
"XOR-N" "XOR" complex-instruction ,
"n" token sp hide ,
] seq* [ no-params ] action ;
: XOR-R-instruction ( -- parser )
[
"XOR-R" "XOR" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: XOR-(RR)-instruction ( -- parser )
[
"XOR-(RR)" "XOR" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: OR-N-instruction ( -- parser )
[
"OR-N" "OR" complex-instruction ,
"n" token sp hide ,
] seq* [ no-params ] action ;
: OR-R-instruction ( -- parser )
[
"OR-R" "OR" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: OR-(RR)-instruction ( -- parser )
[
"OR-(RR)" "OR" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: CP-N-instruction ( -- parser )
[
"CP-N" "CP" complex-instruction ,
"n" token sp hide ,
] seq* [ no-params ] action ;
: CP-R-instruction ( -- parser )
[
"CP-R" "CP" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: CP-(RR)-instruction ( -- parser )
[
"CP-(RR)" "CP" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: ADC-R,N-instruction ( -- parser )
[
"ADC-R,N" "ADC" complex-instruction ,
8-bit-registers sp ,
",n" token hide ,
] seq* [ one-param ] action ;
: ADC-R,R-instruction ( -- parser )
[
"ADC-R,R" "ADC" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
8-bit-registers ,
] seq* [ two-params ] action ;
: ADC-R,(RR)-instruction ( -- parser )
[
"ADC-R,(RR)" "ADC" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
16-bit-registers indirect ,
] seq* [ two-params ] action ;
: SBC-R,N-instruction ( -- parser )
[
"SBC-R,N" "SBC" complex-instruction ,
8-bit-registers sp ,
",n" token hide ,
] seq* [ one-param ] action ;
: SBC-R,R-instruction ( -- parser )
[
"SBC-R,R" "SBC" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
8-bit-registers ,
] seq* [ two-params ] action ;
: SBC-R,(RR)-instruction ( -- parser )
[
"SBC-R,(RR)" "SBC" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
16-bit-registers indirect ,
] seq* [ two-params ] action ;
: SUB-R-instruction ( -- parser )
[
"SUB-R" "SUB" complex-instruction ,
8-bit-registers sp ,
] seq* [ one-param ] action ;
: SUB-(RR)-instruction ( -- parser )
[
"SUB-(RR)" "SUB" complex-instruction ,
16-bit-registers indirect sp ,
] seq* [ one-param ] action ;
: SUB-N-instruction ( -- parser )
[
"SUB-N" "SUB" complex-instruction ,
"n" token sp hide ,
] seq* [ no-params ] action ;
: ADD-R,N-instruction ( -- parser )
[
"ADD-R,N" "ADD" complex-instruction ,
8-bit-registers sp ,
",n" token hide ,
] seq* [ one-param ] action ;
: ADD-R,R-instruction ( -- parser )
[
"ADD-R,R" "ADD" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
8-bit-registers ,
] seq* [ two-params ] action ;
: ADD-RR,RR-instruction ( -- parser )
[
"ADD-RR,RR" "ADD" complex-instruction ,
16-bit-registers sp ,
"," token hide ,
16-bit-registers ,
] seq* [ two-params ] action ;
: ADD-R,(RR)-instruction ( -- parser )
[
"ADD-R,(RR)" "ADD" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
16-bit-registers indirect ,
] seq* [ two-params ] action ;
: LD-RR,NN-instruction ( -- parser )
#! LD BC,nn
[
"LD-RR,NN" "LD" complex-instruction ,
16-bit-registers sp ,
",nn" token hide ,
] seq* [ one-param ] action ;
: LD-R,N-instruction ( -- parser )
#! LD B,n
[
"LD-R,N" "LD" complex-instruction ,
8-bit-registers sp ,
",n" token hide ,
] seq* [ one-param ] action ;
: LD-(RR),N-instruction ( -- parser )
[
"LD-(RR),N" "LD" complex-instruction ,
16-bit-registers indirect sp ,
",n" token hide ,
] seq* [ one-param ] action ;
: LD-(RR),R-instruction ( -- parser )
#! LD (BC),A
[
"LD-(RR),R" "LD" complex-instruction ,
16-bit-registers indirect sp ,
"," token hide ,
8-bit-registers ,
] seq* [ two-params ] action ;
: LD-R,R-instruction ( -- parser )
[
"LD-R,R" "LD" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
8-bit-registers ,
] seq* [ two-params ] action ;
: LD-RR,RR-instruction ( -- parser )
[
"LD-RR,RR" "LD" complex-instruction ,
16-bit-registers sp ,
"," token hide ,
16-bit-registers ,
] seq* [ two-params ] action ;
: LD-R,(RR)-instruction ( -- parser )
[
"LD-R,(RR)" "LD" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
16-bit-registers indirect ,
] seq* [ two-params ] action ;
: LD-(NN),RR-instruction ( -- parser )
[
"LD-(NN),RR" "LD" complex-instruction ,
"nn" token indirect sp hide ,
"," token hide ,
16-bit-registers ,
] seq* [ one-param ] action ;
: LD-(NN),R-instruction ( -- parser )
[
"LD-(NN),R" "LD" complex-instruction ,
"nn" token indirect sp hide ,
"," token hide ,
8-bit-registers ,
] seq* [ one-param ] action ;
: LD-RR,(NN)-instruction ( -- parser )
[
"LD-RR,(NN)" "LD" complex-instruction ,
16-bit-registers sp ,
"," token hide ,
"nn" token indirect hide ,
] seq* [ one-param ] action ;
: LD-R,(NN)-instruction ( -- parser )
[
"LD-R,(NN)" "LD" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
"nn" token indirect hide ,
] seq* [ one-param ] action ;
: OUT-(N),R-instruction ( -- parser )
[
"OUT-(N),R" "OUT" complex-instruction ,
"n" token indirect sp hide ,
"," token hide ,
8-bit-registers ,
] seq* [ one-param ] action ;
: IN-R,(N)-instruction ( -- parser )
[
"IN-R,(N)" "IN" complex-instruction ,
8-bit-registers sp ,
"," token hide ,
"n" token indirect hide ,
] seq* [ one-param ] action ;
: EX-(RR),RR-instruction ( -- parser )
[
"EX-(RR),RR" "EX" complex-instruction ,
16-bit-registers indirect sp ,
"," token hide ,
16-bit-registers ,
] seq* [ two-params ] action ;
: EX-RR,RR-instruction ( -- parser )
[
"EX-RR,RR" "EX" complex-instruction ,
16-bit-registers sp ,
"," token hide ,
16-bit-registers ,
] seq* [ two-params ] action ;
: 8080-generator-parser ( -- parser )
[
NOP-instruction ,
RST-0-instruction ,
RST-8-instruction ,
RST-10H-instruction ,
RST-18H-instruction ,
RST-20H-instruction ,
RST-28H-instruction ,
RST-30H-instruction ,
RST-38H-instruction ,
JP-F|FF,NN-instruction ,
JP-NN-instruction ,
JP-(RR)-instruction ,
CALL-F|FF,NN-instruction ,
CALL-NN-instruction ,
CPL-instruction ,
CCF-instruction ,
SCF-instruction ,
DAA-instruction ,
RLA-instruction ,
RRA-instruction ,
RLCA-instruction ,
RRCA-instruction ,
HALT-instruction ,
DI-instruction ,
EI-instruction ,
AND-N-instruction ,
AND-R-instruction ,
AND-(RR)-instruction ,
XOR-N-instruction ,
XOR-R-instruction ,
XOR-(RR)-instruction ,
OR-N-instruction ,
OR-R-instruction ,
OR-(RR)-instruction ,
CP-N-instruction ,
CP-R-instruction ,
CP-(RR)-instruction ,
DEC-RR-instruction ,
DEC-R-instruction ,
DEC-(RR)-instruction ,
POP-RR-instruction ,
PUSH-RR-instruction ,
INC-RR-instruction ,
INC-R-instruction ,
INC-(RR)-instruction ,
LD-RR,NN-instruction ,
LD-RR,RR-instruction ,
LD-R,N-instruction ,
LD-R,R-instruction ,
LD-(RR),N-instruction ,
LD-(RR),R-instruction ,
LD-R,(RR)-instruction ,
LD-(NN),RR-instruction ,
LD-(NN),R-instruction ,
LD-RR,(NN)-instruction ,
LD-R,(NN)-instruction ,
ADC-R,(RR)-instruction ,
ADC-R,N-instruction ,
ADC-R,R-instruction ,
ADD-R,N-instruction ,
ADD-R,(RR)-instruction ,
ADD-R,R-instruction ,
ADD-RR,RR-instruction ,
SBC-R,N-instruction ,
SBC-R,R-instruction ,
SBC-R,(RR)-instruction ,
SUB-R-instruction ,
SUB-(RR)-instruction ,
SUB-N-instruction ,
RET-F|FF-instruction ,
RET-NN-instruction ,
OUT-(N),R-instruction ,
IN-R,(N)-instruction ,
EX-(RR),RR-instruction ,
EX-RR,RR-instruction ,
] choice* [ call( -- quot ) ] action ;
: instruction-quotations ( string -- emulate-quot )
#! Given an instruction string, return the emulation quotation for
#! it. This will later be expanded to produce the disassembly and
#! assembly quotations.
8080-generator-parser parse ;
SYMBOL: last-instruction
SYMBOL: last-opcode
: parse-instructions ( list -- )
#! Process the list of strings, which should make
#! up an 8080 instruction, and output a quotation
#! that would implement that instruction.
dup " " join instruction-quotations
[
"_" join [ "emulate-" % % ] "" make create-in dup last-instruction set-global
] dip (( cpu -- )) define-declared ;
SYNTAX: INSTRUCTION: ";" parse-tokens parse-instructions ;
SYNTAX: cycles
#! Set the number of cycles for the last instruction that was defined.
scan-token string>number last-opcode get-global instruction-cycles set-nth ;
SYNTAX: opcode ( -- )
#! Set the opcode number for the last instruction that was defined.
last-instruction get-global 1quotation scan-token hex>
dup last-opcode set-global set-instruction ;