On Jan 20, 18:45, Jochen Kunz wrote: About the best use I can think of for a PC/XT :-) If you can find an MRV11-D (to put MXV11-B ROMs into) or an MVX11-B, that would be the best option (and the only ones DEC supported). However, it should be possible to put the code from MXV11-B ROMs into several 24-pin 2Kx8 EPROMs (2716 or equivalent), and put the EPROMs into a BDV11. However, you'd want to modify the BDV11 for 22-bit operation (that's ECO 005). Because old hard drives take a lot of current. The PSU and wiring loom won't take a full backplane and two hard drives. I did one of mine a different way. I have a BA11-N with the backplane modified to be 22-bit. In it is an RQDX2 (or an RQDX3, depending on what's been shuffled around this month), with a 50-way ribbon cable going to a DEC box (used to be a TKZ50) which has a PSU, a hard drive, and an RX50. In the box is also a small PCB I made to do the job of the distribution board found in a BA123. Also in the BA11-N backplane is a modified BDV11, with a pair of 28-pin EPROM sockets which normally hold microPDP-11/23 boot ROMs. -- Pete Peter Turnbull Network Manager University of York