> Does anyone remember if it's possible to run CP/M on a TRS-80 model 4? Yes. I've used Radio Shack's CP/M Plus (returned for refund) and Montezuma Micro's CP/M 2.2, but I ended up writing my own CP/M 2.2 and CP/M Plus BIOS for the Model 4 (along with some utility programs) because I didn't like the existing options. -- Eric Dittman dittman at dittman.net