Reader may be aware of my interest in UNILAB educational modules and the efforts spent previously creating a clone of the 3-Chip-Plus module (based on a 6502 with 2k bytes RAM and a battery-backed RAM module for storing programs). When reading up on this is became apparent that much of the memory map was designed for software compatibility with the BBC Micro range of machines (mostly the memory mapped location of the 6522 PIA which drives the input and output port of the device. Well it turns out that UNILAB also developed an interface for the BBC Micro range of machines (B, B+, Master*) which interfaces to its 6522 using the User and Printer ports of the machine.
*I think the master compact is not compatible since it lacks the User Port.
Earlier this year someone on the Acorn Computer and BBC Micro Enthusiasts Facebook group was kind enough to share some pictures of both sides of the original Unilab Computer Module board. Based on that I’ve reverse-engineered a clone board.
The new module has been developed in KiCad. All design files are available so you can get your own boards manufactured and build one of these. Note that I have compressed the board down to 100x100mm for cheap PCB manufacturers. All design files are on my UNILAB Computer Module Github page (note the errata on the current board version)
Initial tests indicate the module is working well. More to come on that with some software and maybe videos of connected peripherals in action…