Dave,
  What you have there is a Xylogics 753 disk controller.  It's not a
Multibus card; Multibus cards have two card-edge connectors on them,
on large and one small, not VME-style connectors.

  The 753 is a 6U VME card (meaning only two connectors) implementing
a 4-drive SMD disk controller.  It is register- and format-compatible
with the Xylogics 7053, an older 9U (three connector) board commonly
used in high-end Sun server systems.  It is also a fair amount faster
than the 7053.

  3U, 6U, and 9U VME cards (1-, 2-, and 3-connectors, respectively)
differ mainly in physical size.  In the Sun world, it is common to use
6U VME cards in a 6U-9U adapter frame like your 753 is in.

  I am using several XY753's at work, and one at home.  They work very
well and are reliable.  I haven't tried NetBSD with any of them yet,
but I expect that the level of compatibility with the 7053 is such
that it will work.


                            -Dave McGuire
                             Systems Engineer
                             Digital Express Group, Incorporated
                             mcguire@digex.net


On December 20, you wrote:
> 	Ok... found a card... I don't really know what it is.  It was
> in the back of a Sun3/260 (or something similar... there is 4 meg on
> the CPU card ... but it's the same chassy as the 3/260).  It is a VME
> card ... or maybe more properly a Multibus card (as it only has two of
> the three connectors).  The components are far too new, however, to be
> Sun3/260 or even Sun4/260 vintage --- there are lots of tiny surface
> mount and PLCC chips.
> 
> 	There are 5 connectors on the back.  One connector is larger
> than the other four and looks like the tiny-style SCSI connector (HP
> and Sun use them, I believe).  By my could-be-wrong count, it has 60
> pins.  The other four connectors are the same style with only 26
> pins.  The back of the VME board is cut out to let round cables pass
> out of the machine.
> 
> 	There are 2 xylogics chips on them.  One VMEDMA 176-120-001
> and the other REGCEL 176-121-001.  The other large PLCC is LSI LOGIC
> L1A4378.  What looks to be a ROM is (c) AMD and labelled 27C256 on the
> chip and E2271 2.2 // 5763*753 on a label on the chip.
> 
> 	An interesting feature of the board is that there are dozens
> of terminating resistors on it... many dozens.  There are also 4 large
> very well heat-sinked devices that I suspect are transistors.
> 
> 	The back of the board is labelled with two stickers.  One
> X9420849 and the other 753-107-216 // B-D-2.2
> 
> 	The front of the VME holder for this card (it's really quite
> small) is labelled with Integrated // Resources // Model
> No. 0961FB5XYL // Serial NO. 387 // made in U.S.A
> 
> Dave.
> 
> -- 
> ----------------------------------------------------------------------------
> |David Gilbert, PCI, Richmond Hill, Ontario.  | Two things can only be     |
> |Mail:      dgilbert@pci.on.ca                |  equal if and only if they |
> |http://www.pci.on.ca/~dgilbert               |   are precisely opposite.  |
> ---------------------------------------------------------GLO----------------