ITI Audio/Sontec is known for world-class analog mastering equipment, but in the 80s they designed and prototyped a FORTH computer based on the Rockwell R6500 series CPUs:

http://www.glitchwrks.com/2022/09/28/so ... h-computer

Here's a picture of the last assembled stage of prototyping:



There's actually a further revision for which we have acetate artwork and a blank prototype board, but the schematics have been lost, and the prototype is from the 1980s and does not have plated-through holes! The Sontec FORTH computer was a big inspiration for our own R65X1Q SBC:

https://www.tindie.com/products/glitchw ... -computer/

The ICs purchased for the development of the Sontec FORTH computer are where the images for RSC-FORTH that we recovered came from:

https://github.com/glitchwrks/rsc_forth

Have you gotten this computer running, or are you just collecting them?

I've gotten it running, and reverse engineered the bodge board enough to replace it with a GAL (I've written the PALASM but have not yet dropped it in, it'll require one jumper modification). This board was also largely the inspiration for the R65X1Q SBC!

Neat, glad you got a running. I think this may be the slowest moving forum discussion I have participated in.