The big XY mux is finally gone! I’ve been bumping up against limits in this part of the design since 2014-06-03, but it’s all sorted out now. I moved the Memory Read bit in microcode up to make room to […]

Implemented high-byte loads for the 8-bit registers, tests for these all now exist and pass. Started thinking about implementing shifts, looked at barrel shifters but they’re far too much logic for now (~64 muxes, which would be ~128 chips), and […]

Thought a lot about whether 64k per page table block is really enough space, extensively considered going to 9bit bytes and 18bit alu/registers. Eventually decided against it after a lot of consideration, as I think it would make interop with […]

Fixed a significant bug in the functional simulator test functionality, it was testing at the wrong moment and also skipping tests at HALT time. Both are now fixed, and sub8.ab passes all tests (it was failing ~60% before).

Test Console in the functional simulator now mostly functional, a couple loose ends to tie up, mainly the fact that it doesn’t appear automatically when a test is loaded, you have to manually show it before loading the ROM.

Started working on a separate Test Console window for the functional simulator that lists all the steps of the test, and displays the status and expected/found results for each one.

Implemented the rest of basic test functionality for the functional simulator, simple tests now run successfully.

Finished implementing paging in the functional simulator, all working now. Started implementing functionality to run the same test cases the Verilog simulator does, all the functionality to read ASCII-binary test files and build a list of test steps is now […]

Finished migrating the memory display in the functional simulator over to a table and implementing highlighting of where PC currently points. Started adding a page table display as well, this is still a work in progress.

Added a diagram of how paging is set up, and started working to move the memory display in the functional simulator from a text box into a proper table, so we can do highlighting and such. Not done this yet, […]