Cabling a TRS-80 disk drive is a bit tricky. It works differently from a PC, and there are some differences among the TRS-80 models, and differences between the Radio Shack way of doing things and other ways that are sometimes used. I’m sorry there is so much detail here, but I don’t really see how to condense it to a cookbook “just do this” approach, since there are several things you might want to do with the information. Generally, Radio Shack handled drive select by pulling pins in the cable connectors. On the Model I, each drive was internally jumpered to respond on all four different drive selects, the three standard ones from the Shugart definition (pins 10, 12, 14) and one extra one that R.S. defined (pin 32, which later was officially defined as side select for two-sided drives). On the cable, there were four drive connectors, and each had a different one of those four pins left, with the other three removed. On the Model III and 4, the internal drives and external drives were