convert RX01 to RX02?

There are 2 large boards bove the chassis, the top one (on a hinge) is the controller, the lower one is the read/write board. Those boards are bot different betwee nthe RX01 and RX02, and you must have a pair from the same type of drive. There's no (simple) way to use an RX01 controller with an RX02 read/write or vice versa. It sounds like you have a pair of RX02 boards though which will work together. I think the itnerconencting cable between them is differnt between an RX01 and RX02, but that it not a major porblem The pwoer supply is indentical between the 2 typs of drive. So is the chassis and the fan plenum The drives are almsot the same. From what I remember (and you'd have to check the prints or the pocket service guide), there's a resistor (1k?) between pins on the head conenctor that must be fitted if it's ued with one type of read/write board and remvoed for the other. I think all spare drives came with it fitted, and you diked it out if you were fitting the srive to the other type of unit.. IIRC, on a PDP11, you have to use an RX02 bus interface (RX211, RXV21) to use double-density, If you have an RX11 or RXV11, you can only use the thing as a single-density drrvie even if you fit the RX02 boards. Conversely, an RX211 or RXV21 will not work with an RX01. On omnibus PDP8s, the RX8e card wil lwork with boat types of drive unit, and will do sdobule density on an RX02. In one respect the RX01 is more interesting. There's a 36 pin edge connector on the controlelr PCB. It's to connect a KM11 maintenance board which will then dispaly th microcode PC, various flags, etc. And one of the switches on the KM11 does a halt-microcode-on-errrr. I ratehr enjoyed debugging mine that way. For the RX02, you need a logic analyser to figure out what the microcode is doing. -tony