Be very careful with that chassis! If it was really a MicroPDP, it will have an 18 bit qbus backplane in it. It will _destroy_ 22 bit qbus boards since there are power pins on the 18 bit bus that mate to data pins on the 22 bit bus. Then again, my memory may be completely broken and I've got it all wrong. :) g.

----- Original Message ----- From: "no" <oliv555(a)arrl.net> To: <classiccmp(a)classiccmp.org> Sent: Wednesday, October 18, 2000 9:05 PM Subject: BA23 w/RA70 Actually, this is a long-held question of mine too :) I've got a MicroVAX III in my basement in a BA123 with four RA72 SDI drives and a KDA50 controller. Unfortunately, I didn't get any cables for connecting the card to the drive when I purchased the card, and I really don't know much at all about the SDI disk interface in the first place. Just out of curiousity, does anyone out there have a pointer to a site that has a good file explaining SDI, or would anyone be willing to explain the basics? Do I need anything else besides the card and the drive (like this RA-series control panel mentioned in the previous message)? How are the drives cabled to the card? Is the cabling something relatively straightforward that I could put together myself? I think it would be cool to get the system running with them; they've been just kind of sitting in the basement as a "to-do" project someday. Thanks, --Sean Caron (root(a)diabloent.net) | http://www.diablonet.net