68xx cross assembler
I've gotten quite a few questions now about my assembler and workflow for the MC3. I've used the same old 6800/01/04/05/09/11 assembler for years. I think it's made by E J Rupp originally. It's very basic and does not handle macros and such but it's clean and I do have the source code and have made a few modifications over the years. Mainly adding a version (as1h) that supports the very useful XGDX opcode for 6301/6303. The output is Motorola S-record (S19) that is directly compatible with most monitors and PROM programmers. Below is an archive of the assembler with both source and Linux binaries. Download assembler source and binaries I have included a build script (build.sh) for compiling under GCC. Assemble and generate s19-file $ as1h program.asm Assemble and generate listing + s19 $ as1h program.asm -L > program.lst As for assembler editor I use Emacs all the way. It handles 68xx assembly nicely.
by DJLinux 2017-03-23 04:30 UTC
in some files you define two different commands with the same opcode 0x8D=141 "bsr", 141 "jsr", 0x8D do you mean 0xBD "bd" not "8d" ? DJ


by daniel 2017-03-23 07:29 UTC
Hi Dj! I understand the confusion. Actually the op codes that have all the addressing modes IMM, DIR, IND and EXT are represented in the table in their IMM form. That's why the JSR becomes a BSR. The assembler sets bits 5 and 6 in the op code according to the addressing mode specified during assembly. Hope that clears it up a bit. I can't explain the sudden mix of decimal and hexadecimal numbers the source code. I blame temporary delirium, sleep deprivation, position of the planets or possibly the cat :)


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