Re: AW: [pups] 2.11BSD disklabel-programm

On Jan 20, 2:05, lothar felten wrote: Sounds like you have what was a standard PDP-11/23 (or maybe 11/23+) system in an office-type cabinet (H9642 or equivalent), with an RL02 in the top, a stiffener panel, BA11-N or BA11-S box, a second RL02, and two blanking plates at the bottom. Sometimes people moved the second RL02 down 3U and put one blanking plate or an expansion box between the BA11 and the RL02. As far as I remember, the only significant difference between a BA11-N and a BA11-S is an uprated power supply, and a 22-bit backplane instead of an 18-bit one (but you can upgrade the 18-bit ones). Correct. There is a very similar backplane H9275-A which is all serpentine, but not in a standard 11/23 box, as far as I remember. H9276-A is for a BA11-S. BA11-N uses H9273. OK. That should be fine, so long as there are no gaps in the A/B slots (left side of backplane as you look into it from the back of the machine) between the cards. The original 11/23+ probably had an RQDX1 or RQDX2, and possibly an RLV11, and certainly different memory. The -AE means it's a later board, should be 18MHz, and should not only be FPU-capable, it should actually have the FPJ-11 chip on it. -AD is the same thing without the FPJ-11 fitted (it still does floating point ops, just more slowly). If not, you'll probably find it easier to get a replacement board with an FPU already on it, rather than get the FPU chip on it's own. To get the best performance, yes. It won't double the speed, or anything like that, but it will go a bit faster. If it's an H9276 backplane and H7861 PSU, yes. Not quite factory-standard :-) But none the less good. -- Pete Peter Turnbull Network Manager University of York