Q-BUS primer?

On Thu, Jan 31, 2008 at 08:40:35AM -0800, Zane H. Healy wrote: A BA-23 will work fine for PDP-11s as well... they were sold as "MicroPDP" systems. While a KDF11-A (half-height 11/23 CPU board) will work, it's probably not the best choice, since a KDF11-A is a CPU only, no peripherals. In the MicroPDP line, one common low-end option was an -11/53 CPU board (can't recall the exact part number, but it might be KDJ11-mumble). There was also the -11/73 variety (definitely something like a KDJ11-B), the same J-11 CPU as the -11/53, but clocked a bit faster (and originally priced a bit higher). Some of the J-11 quad height boards have on-board memory (like the -11/53), I think some do not. These are new enough that my experience is a little fuzzy from the old days. I do have an -11/53 board w/1MB onboard, but it came from a different sort of box than a BA-23, and I haven't played with it much. Also, if you are inexperienced with Q-bus, you might not realize that the BA-23 has two flavors of slots. In a standard MicroVAX configuration, it really won't be a problem, as the CPU and memory occupy the top three slots, the ones that are different. The bottom six slots are idential and "standard" Q-bus. If you are trying to configure something out of the ordinary, it will probably come up as an issue. Not to fill a page with the details, but the keywords are "CD interconnect" and "AB-AB" or just plain "Q22" slots. You can probably search the message archives for this group and see lots of details of Qbus backplanes being discussed here in the past. 11/23 and 11/23+ enclosure. Another BA-11, but I forget the letter designation off the top of my head. I don't recognise those particular devices, but the MSV05B sounds like a tape controller, especially with a pair of 50-pin connectors. That's standard for a Pertec-formatted tape drive interface. Andromeda makes a lot of powerful peripherals, especially disk controllers. I don't know specifically what a UDC-11 is, but have a look for anything that might suggest it's a SCSI interface (NCR or National SCSI controller chips, three adjacent SIP resistor packs for termination...) Xylogics was heavy into terminal servers and serial comms. Perhaps the Wizard 1 is a multi-serial interface. The part number of the DSC-RXVZ1 suggests it is at least a floppy controller, but perhaps it is also a hard drive controller. If so, it probably needs some external breakout board in the same way an DEC RQDX1/2/3 does. If not, it might be just an 8" drive interface for a raw drive like an SA800-series drive (not an RX01 or RX02). It would likely _emulate_ an RXV11 or RXV21 at the register level, but use inexpensive (at the time) non-DEC drives with a 50-pin interface. -ethan -- Ethan Dicks, A-333-S Current South Pole Weather at 31-Jan-2008 at 21:00 Z South Pole Station PSC 468 Box 400 Temp -39.5 F (-39.7 C) Windchill -64.1 F (-53.4 C) APO AP 96598 Wind 8.2 kts Grid 349 Barometer 680.5 mb (10609 ft) Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html