Did more work on the functional simulator, it now executes the ldi16.a test from start to finish without issues. It still doesn’t support paging, any of the FLAGS, and a lot of other microcode features.
Worked on the functional simulator a bunch more, it now gets 3 microcode steps in before dying, which is progress!
Started moving the basic Swift simulator from command line bits into XCode and building the actual GUI for it.
Started working on a high-level simulator to use in working out the final instruction set before finalizing hardware. I decided to learn Swift as I do it (since I wanted a GUI simulator and Swift seemed one of the better […]
Realized there’s no reason to have a Z register at all, X and Y need it since their inputs both come off the shared XY input bus, but with Z every time we load it we immediately then use the […]
Wrote a tool that generates digraphs out of the microcode. Also did a bunch of prep work that had to be done before doing more interrupt work, now have instructions to disable/enable interrupts and can individually set/reset FLAGS bits (instead […]
Finished converting all of the unit tests to seasm. Implemented the basic hardware so that interrupts are able to force a jump to microcode interrupt vectors rather than IR when a fetch/execute next happens. Also moved ECLair into a test […]
Started working at moving the unit tests over to seasm rather than raw binary. At this point most of the 8 bit operand tests are moved over, but the “assembler” doesn’t support 16-bit operands yet so that will be the […]
call/ret are finally done and have passing unit tests! Started work on interrupt logic, but ran into an issue that there are no inputs left on the X/Y mux to get the interrupt vectors in anywhere. For the time being, […]
Added realistic propagation delays to alu4 and finished the RAM delays, fixed a couple timing issues and tests all pass at 25MHz and 33MHz now. Am going to leave the clock at 25MHz for the time being, as that’s the […]