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dasm-assembler / dasm

Macro assembler with support for several 8-bit microprocessors
https://dasm-assembler.github.io/
GNU General Public License v2.0
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[REQUEST] 65816 16-bit processor support for DASM #106

Open TheRealHamtaro126 opened 3 years ago

TheRealHamtaro126 commented 3 years ago

Hey there, I tried this assembler before, and it has improved from the days of old where it had no INCBIN, now it has INCBIN... So proud, But that is not why I am here...

Ever since new processor options came built-in to this assembler, hoping for someone to add 65(c)816 support to the latest version. with complete opcode support. used in the SNES, Apple ][GS, and the Commodore 64, as well as some homebrew experiments.

Can it really be supported?

thomas374b commented 3 years ago

This task could be in the range from "easy" to "complex".

0) find out which processor-definition in dasm is the closest match 1) find out which opcodes/mnemonics have been added with this CPU-variant 2) find out which addressing modes have been added with CPU-variant

If there are no new addressing modes (compares to what is already implemented) the task is (easy) only to define a new processor, copy paste one of the mneXXXX.c files and edit and finally test it.

If new addressing modes or some fancy bit-branching comes with the new processor, the task would be rather "complex". Dasm has already support for "some fancy bit-branching" for some processors. Good if the new processor could be somehow "fitted" in the existing implementation. More complex if it can't.

Alternatively one can start with a subset that includes all already implemented addressing modes and add the more complex mnemonics later. If some of the not-yet-implemented mnemonics are needed, they could be replaced by macro definitions from the user.