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>> Says coding the assembly on them is superior to any other option for medium to large use cases. I still have a preliminary instruction set manual for the 68

>> Says coding the assembly on them is superior to any other option for medium to large use cases. I still have a preliminary instruction set manual for the 68000 printed in 1979. At that time I was learning 8080A machine code. When I saw that book the hardware became something I HAD to get my hands on eventually. I finally got to code one in assembly in college and it was every bit as enjoyable as I had imagined. BTW my dad wrote a disassembler for the 8080 in basic, and to simplify everything he rewrote all the mnemonics in a far simpler form than the official syntax from Intel. I still have the 16x16 instruction map. Because of that, the 68000s primary advantage was the increased number of registers and their 32bit size along with some better instructions. The pain of proper 8080 syntax was never a thing for me.

cxr 5y ago
> my dad wrote a disassembler for the 8080 in basic, and to simplify everything he rewrote all the mnemonics in a far simpler form than the official syntax from Intel If you or he still has his notes, would you be able to ZIP them up and upload them to archive.org?
- phkahler 5y ago
  >> If you or he still has his notes, would you be able to ZIP them up and upload them to archive.org? Not sure why, we were the only 2 people on earth to ever use that. To summarize, he used single letters for verbs and then single letters for register names: a, b,c, d,e, h,l for the 8-bit registers and x,y,z for the 16 bit pairs (b,c) (d,e) (h,l). It turns out you could always figure out some implied stuff. MAY was move a to y, but since A is 8 bits and Y is 16 this meant Y was an address, whereas MAD would be move A to D as an 8 bit register-to-register copy. This lead to all mnemonics being 3 characters or less. There could also be 8 or 16 bit immediate values. The disassembler used a 4 byte decode table - 3 characters and a size (0,1,2) of the immediate data. It was super clean. I'll post is somewhere some day. I still have my Interact computer in its original box waiting to find a nice museum somewhere. And lots of tapes including a bunch of little kid created basic programs. Hard copies of all the "Interaction" newsletters from the local users group too.
  - BBC-vs-neolibs 5y ago
    That as a blog post, optionally with your software downloadable, would be a nice addition to the history of the personal computer. (Just link your blog to archive.org then )
mark-r 5y ago
I wrote a disassembler for 68k in 68k assembler. It was part of a home brew monitor, so you could show the code you were executing.

cxr 5y ago

> my dad wrote a disassembler for the 8080 in basic, and to simplify everything he rewrote all the mnemonics in a far simpler form than the official syntax from Intel If you or he still has his notes, would you be able to ZIP them up and upload them to archive.org?

phkahler 5y ago
>> If you or he still has his notes, would you be able to ZIP them up and upload them to archive.org? Not sure why, we were the only 2 people on earth to ever use that. To summarize, he used single letters for verbs and then single letters for register names: a, b,c, d,e, h,l for the 8-bit registers and x,y,z for the 16 bit pairs (b,c) (d,e) (h,l). It turns out you could always figure out some implied stuff. MAY was move a to y, but since A is 8 bits and Y is 16 this meant Y was an address, whereas MAD would be move A to D as an 8 bit register-to-register copy. This lead to all mnemonics being 3 characters or less. There could also be 8 or 16 bit immediate values. The disassembler used a 4 byte decode table - 3 characters and a size (0,1,2) of the immediate data. It was super clean. I'll post is somewhere some day. I still have my Interact computer in its original box waiting to find a nice museum somewhere. And lots of tapes including a bunch of little kid created basic programs. Hard copies of all the "Interaction" newsletters from the local users group too.
- BBC-vs-neolibs 5y ago
  That as a blog post, optionally with your software downloadable, would be a nice addition to the history of the personal computer. (Just link your blog to archive.org then )

mark-r 5y ago

I wrote a disassembler for 68k in 68k assembler. It was part of a home brew monitor, so you could show the code you were executing.