acme/docs/cputypes.txt
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ACME
...the ACME Crossassembler for Multiple Environments
--- cpu types ---
ACME supports the following cpu types:
*** 6502
This is the instruction set of the original NMOS 6502 designed by MOS
(later CSG).
There are 151 documented opcodes.
ACME does not use "A" to indicate "accumulator addressing"; just write
the mnemonic without any argument: "LSR" will work, "LSR A" won't.
*** 6510
This is the 6502 variant used in the C64 computer. It uses the same
instruction set as the 6502, but in addition to that, ACME supports
most of the undocumented opcodes as well.
See "docs/Illegals.txt" for more info.
*** 65c02
This is the CMOS re-design of the 6502. It seems to have also been
available from Rockwell, GTE/CMD and others. Features:
- new instructions:
BRA branch always
PHX/PHY/PLX/PLY push/pull X/Y register
STZ store zero, 4 addr modes
TRB test and reset bits, 2 addr modes
TSB test and set bits, 2 addr modes
- new addressing modes for existing instructions:
LDA/STA/ADC/SBC ($12) zp indirect
AND/ORA/EOR/CMP ($12) zp indirect
BIT #$12
BIT $12, x
BIT $1234, x
INC increment accumulator
DEC decrement accumulator
JMP ($1234, x) x-indexed indirect
- bugfix for flags in decimal mode
- bugfix for JMP($xxff) instruction
- undocumented opcodes are NOPs (although of different lengths)
There are 178 documented opcodes.
*** r65c02
This is a superset of 65c02, probably originally from Rockwell.
- It adds bit manipulation instructions:
BBR0..BBR7 branch on bit reset
BBS0..BBS7 branch on bit set
RMB0..RMB7 reset memory bit
SMB0..SMB7 set memory bit
Chips with this instruction set seem to have been available from
Rockwell, GTE/CMD and others.
There are 210 documented opcodes.
*** w65c02
This is a superset of r65c02, originating at WDC.
- It adds the STP and WAI instructions.
There are 212 documented opcodes.
*** 65816
This is a superset of 65c02, originally designed by WDC (it seems to
have been available from GTE/CMD as well). Features:
- register sizes can be changed to 16-bit
- 24-bit address space
- several new addressing modes
- block transfers
There are 256 documented opcodes, but one of them ("WDM") is reserved
for future expansion.
See "docs/65816.txt" for more info.
*** 65ce02
This is a superset of r65c02, originating at CSG. Features:
- Z register
- 16-bit stack pointer
- 16-bit branches
- a few 16-bit instructions
- new addressing modes
There is a known bug: SBC does not work correctly in decimal mode.
There are 256 documented opcodes, but one of them ("AUG") is reserved
for future expansion.
ACME uses different mnemonics for old ("near") and new ("far") branch
instructions:
BEQ old, 8-bit offset
LBEQ new, 16-bit offset
The original datasheet called BRA ("branch always") BRU ("branch
unconditional") instead. ACME accepts both mnemonics.
*** 4502
This is basically the same as 65ce02, but
- MAP replaces AUG
- EOM is synonymous to NOP
This cpu core can be found in the CSG4510 chip in the C65.
There are 256 documented opcodes.
*** c64dtv2
This is the cpu in version 2 of the C64DTV. It uses a superset of the
6502 instruction set. Features:
- new instructions:
BRA $1234 branch always
SAC #$12 set accumulator mapping
SIR #$12 set index register mapping
- support for some of the undocumented opcodes.