Toolchain update 2

Last time I mentioned that LCC port required updates to the instruction set. Indeed, I decided to give up some instructions in favour of those which seemed to make more sense in view of code generation. I did a major ISA cleanup: I have removed register indirect with register offset addressing modes like in LD ...

ANSI C compiler for BYTEC/16

It’s been over six months since I last posted but I haven’t dropped out of the project completely. I have been slowly and quietly working on an initial revision of LCC port in short weekend sessions (not more than 2 hours each week). The reason for losing momentum a bit is my daughter Viktoria’s birth ...

New memory & next steps 6

New memory & next steps
I have been unable to spend much time on the project lately, so there is no important milestone to report today. Still, some time ago I soldered the new memory board, implementing the banked model described in this post, and extending the original idea. It worked at the very first attempt, so I have no ...

UART board soldering and bring-up 3

UART board soldering and bring-up
The UART board from BatchPCB must be cursed. First, it took it (and the accompanying new memory board) over four months to get here, then it silently refused to cooperate when I finally soldered it. I was surprised, as it was really an easy board to design and solder, with only few components and lots ...

Yet another instruction set update

Some time ago, when fiddling with my Monitor/OS program I decided to make a few changes to the instruction set. I guess that’s the real flexibility when you build your own CPU – if you don’t like the instruction set, and you suddenly come up with a need for an instruction that is missing, you ...

New boards arrived

New boards arrived
Finally, after a very long wait, I have found an envelope from BatchPCB in my mailbox. I placed an order on November 1, 2011 for two euro sized boards in a hope that I would receive them after three to four weeks. I received them last week, so after more than four months. That’s way too long. ...