Having got a TMS9995 system on RC2014 working as far as the monitor I still wanted to run BASIC and Forth. I’d not been able to get my pageable ROM card working, and the switchable ROM module is too small. But it’s too small because it’s designed to carve a 64K EPROM into 8K pieces. All I had to do was take the gating out of the A13 and A14 lines. That took a couple of jump leads and a solder blob on the back:

and disconnecting U2A:

I can now use the A15 jumper to choose between BASIC:

and Forth:

It’s all a bit hacky, but a lot less work than making my own ROM module from scratch.

Next post: Retro Computing – Final Touches for TMS9995 on RC2014