A more obscure language from decades ago - FORTH. I never understood it back then, but just shows it's never too late to learn :)

BASIC Interpreter development

CoPEx - Cooperative PlaMa Executive

Part 1 of an experimental executive program

Programming walk-through - 3-part video series

Full walk-through of latest programming route using plasm assembler.

Season's greetings

Main memory increased from 2K to 64K words for the PleX ISA. This was part of an upgrade exercise using re-tracked PCBs, and was the final planned hardware change. Future updates will be firmware-only.

Floating point functions added to PleX . This has not been rigorously tested yet, apart from running Lunar Lander :) but any fixes will only require firmware updates.