I got the stuffed prototype boards back for my "unibus device emulator" today. Here's a poor picture (I was in a hurry) http://www.heeltoe.com/retro/udisk/udisk_big.jpg I powered it up and after fixing a few problems got everything on the "top half" of the board to work, basically cpu, serial port, led's and CF disk. I'll add some ttl chips tomorrow and check out the unibus interface. The (now out of date) docs are here http://www.heeltoe.com/retro/udisk/index.html It's a very simple design - basically an ARM cpu and a CPLD with lots of unibus receives and transceivers. Most of the work is done in software. The idea is the "personality" is specified by a file on the disk. There is also a serial port and USB. Both CF and IDE notebook drives are supported (a normal IDE can also be used with an adapter). I will update the doc files and publish the schematics, cpld files and source code - for non-commericial use anyway. So far I've written some simple code to emulate an RL02. I think I'll do an RK05 next. At some point I'll do a UDA50 also. It can also be used to talk to other controllers, test ram, etc... I don't know if it will actually work (yet), but it should be capable of emulating ram, rom or any unibus device. All of the control signals are there. The CPLD has two address comparators (with mask) which generate an interrupt to the cpu. The cpu then runs the bus cycles "by hand". I included the A,B parity lines also (to the cpld anyway) so it should be able to do 18 bit i/o. At some point I'd like to con someone into working on a massbus/rp03 style controller. This board should be able to go into the "magic" unibus slot on a KS-10 (it's only magic because of the bus hog disk controler which normally goes there). If, once it works, anyone else would like one I'd like to make a run of 10 or so with gold edges (and no mod wires :-) I estimate the cost would be about $200 each. Half of that is the pcb, the other half parts. I'd be happy to sell blank boards also, if people like to solder :-) All of the parts are available from Digikey, except the DS8641 & DS3862's. I'm going to use DS8838's instead of DS8641's, because I have a few (I need 2 per board). I also have about 200 DS3862's. The design uses 7, so 200/7 = 28 :-) it's just a hack, but should make my unibus machines happy :-) -brad