2015-12-03 12:05 UTC
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
do you mean 0xBD "bd" not "8d" ?
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 :)
by Grant B 2018-01-23 18:07 UTC
If I may be so bold as to bookmark a couple more assemblers that work for the 6303 (and many other) CPUs. Both also come with source code.
The one I am using now is called DASM-2.20. It an unfortunate name for an assembler (rather than a disassembler), but it supports many CPUs and is pretty good. Here is one "source" for it (there are binaries):
However, the one I really want to use is the Alan Baldwin one. I just have to find some binaries as I don't think I have the tools to build it anymore. (I have used this family of assemblers for decades for many old Motorola projects like 6809 and 68HC11. And now I want to port some of that old code to the 6303):
I hope this helps someone.
by Grant B 2018-01-23 18:16 UTC
And for completeness I should perhaps add one more. It says it supports the Hitachi 6301 (as well as many more targets of course). I have not used it (yet) and it's simply called "AS".
And one question: Are there any books or textbooks on this family you recommend?
by skipp 2019-03-25 07:18 UTC
Hello Grant B. I found your above comments in March of 2019, but the link to the asxxx assembler is a wonderful thing, thanks for providing it. Not to mention, the assembler package was just updated to 5.31 this month. I'm going to be weighing the asxxx and dasm assemblers against each other to pick the best one for me.
skipp025 at yahoo dot com
by Luigi 2019-09-11 19:32 UTC
For your consideratin: I found a C cross compiler from H-Tech native into cp/m ambient buried in a z80 C compiler package.
It seems very intereresting.
At the follow link you can find the motorola.exe zipped file with a lot of cross assembler
There is a 6301 option
by Kip - computerdoc 2022-09-09 02:05 UTC
ASxxxx Cross Assemblers are now updated to v5.41!
Daniel, I really love your HD6303rp MC3 microcomputer design!
I have begun entering your MC3 schematics into Eagle Pro one board at a time in preparation to fabricate some PCBs. When I am done, I will need several MC3 enthusiasts to pour over all the schematics to ensure they are correct. You all can contact me at computerdoc at sc dot rr dot com should you be interested in helping. Be sure to at least put "MC3 Computer" in the Subject of the email.
Daniel, I would really appreciate your help in this endeavor as well. Should you be interested in adding any new features on any of the boards, please let me know.
My 1st microprocessor I ever studied in College many years ago was the MC6800P! It has had a special place in my heart ever since!
Take care my fellow enthusiasts! Have a great day!
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