You really don't need anything other than a RAM upgrade to run CP/M on them. I have three Indus GT, but one is in storage somewhere and I can't account for it I will always standby my notion that the Indus GT is the coolest looking (even sexy in an early 80s type of way) external floppy disk drive of the 8 bit era. Speaking of upgrading the Indus GT, I have ordered the 64KB RAM upgrades for both of mine. One will be used from time to time for CP/M stuff. One will be used in a really bastardized Atari 8 bit setup That machine will be running a Hitachi 6309 instead of a 6502, and will run the NitrOS 9 OS meant for the CoCo 3Just dropping in to register agreement--I had one of those back in the day with my 400. I'm not sure I agree with the "for those old machines" qualifier, though.
While looking for a picture just now I ran across a forum post from 2018 where someone created a daughterboard for the GT that would let you run CP/M on the disk drive's controller and use your Atari as a terminal.
In any case...if someone happens to see this and has an Atari Indus GT (or Percom, or Amdek 3" floppy, or even a good working 1050) disk drive and wants to sell it, I am in the market for a few more (would like to have 8 Indus GT drives). As far as that goes, if anyone sees this and has any old 8 bit gear they want to sell, I am open to it