--- Doc Shipley <doc(a)mdrconsult.com> wrote: I think I have one or two of these. Never powered them on. Got them in a pile of spare SI9900 parts over 5 years ago. The connector to the 9900 is a pair of BC08 cables (40-pin ribbon cables) I have never used a 9900 with a MicroVAX, but we used to use one every day on our 11/750 with a Massbus adapter. There was an SI- specific cable set that went from the 11/750 backplane to a pair of 40-pin connectors that did not resemble the 3-tier Massbus connector. The two 11/70s I got a couple of years ago both came with 9900 adapters. I would have to poke around with a flashlight to report how they attach. The arrangement was this... Some sort of host board -> SI9900 -> one or more SMD drives. You could plug multiple hosts into one SI9900, but we never did. You could plug multiple disk boards into it, too, and we did do that, IIRC. The SI9900 itself is a 5"-tall rackable box with a PSU and two bays for cards. They stacked on the left and on the right - one for host cards (with a pair of 40-pin cables going to each host) and one for drive cards. It's been so long since I've been in one that I forget if the drive cards supported multiple drives per card. Ours had a 160MB Fujitsu drive and an Eagle; I don't recall how many drive cards were in the 9900. We didn't have to patch the OS to access the 160MB Fuji as two 67MB devices, but we did have to wait on SI to upgrade VMS until they released a patch for the DRDRIVER (IIRC) to add/modify an entry for our oversized RM05 (~400MB). Obviously, the SI9900 works with the PDP-11/70, but I have no experience with it. I do not know what device the Qbus board resembles. If you don't have the 9900 itself, that card isn't going to do you much good. I don't know why we went with the SI9900, but it would have been c. 1983 or 1984. It was probably the fastest, cheapest way to throw some disk on our *new* 11/750 (BT0000354) About the same time, an RA81 was $26,000 plus the cost of the UDA-50. A Unibus SMD interface might have been cheaper, but not as fast. -ethan __________________________________________________ Do You Yahoo!? Yahoo! Tax Center - online filing with TurboTax http://taxes.yahoo.com/

Hi Doc, I have a pair of SI 9900 controllers that I THINK will work with your QBus board. They are rack mount drawers about 4" high with boards and stuff in them. I believe they are complete, they were closed with the screws installed, but I don't have an interface card for them. Actually, I may have a pair of QBus cards that will drive them, but they are connected to another pair of SI boxes with controllers inside. I also have documentation for the QDA50E which I believe to be the QBus version of the 9900 and software drivers and formatters on TK50 for the same. If you are interested in these, let me know, and I'll figure out the shipping (or you can pick them up next time you come through Denver). Regards, Clint On Sat, 6 Apr 2002, Doc Shipley wrote: