Robotool used to be up in Broomfield, CO near the airport there. Atleast at one point when I went up for a look.
The CVM-1 which was there most popular model used Z80A CPU's if I recall. I think it used a CPM Operating system. Program length was rather limited - but it did have the ability to chain programs. When it hit the end of part of a chained program the spindle retracted (running) and paused while the next program in the chain was loaded from floppy. The next program would continue once loaded.
Most were built on big knee mill iron sometimes sold under the "Mighty" name. ( I seem to remember a "M" cast into the main part.)
Personally - I would consider a CVM-1 a starting point for a decent EMC2 retrofit. - the servos, amps, powersupplies could all be reused.
Note: that due to the Z80A cpu the CVM1 only had .001" resolution and updated encoders would provide better results.
(Note also later on Robotool did have a 80286 control, but I don't think many were sold.)
I have no connection with them - I just looked into buying one - Twice.