Where does it say this? (I didn't search for that.) Rotsa ruck! They're down the same mine as Jimmy Hoffa!! :-) But seriously, if you could find them, that would be fantastic. I've managed to collect (thanks Clem!) a tiny bit of info about them: http://gunkies.org/wiki/Able_ENABLE and I _think_ I've worked out how they worked, but more is better. We had a set of the prints at MIT BITD, but we didn't have the PROM/PLA/PAL/etc programming info, and one would need that too to reproduce them. they So Dave Bridgham and I have been working on a QBUS card with an FPGA that uses an SD card to hold the bits, and emulates an RK11/RP11/etc controller. We have a wire-wrap prototype working (the RK11's done, the RP11 should be a short edit of that), and UNIX boots and runs. Now to turn it into PCB's... We've planned that the next step will be to do a UNIBUS version, which will also include ENABLE functionality (although it won't be plug compatible with an ENABLE, the memory will be on-board). Now to find the time/energy to make it happen... :-( Noel