[comp.sys.dec] How to tell the differece between Unibuss and Qbuss?

Azog-Thoth@cup.portal.com (William Thomas Daugustine) (12/23/90)

Well, the header pretty much tells it all...

How does one tell the difference between a Qbuss module and a Unibuss
module? Physcally, that is. Ive never had the pleasure of working on
Qbuss stuff, and have a memory card that I dont quite know what is.
Its a National Semiconductor memory card, stocked with 64k drams.
It would either be a duel height Unibuss card (is there such a beastie?)
or a Qbuss card. If its Qbuss, its useless to me, but if its Unibuss, 
Id like to put it in my PDP-11/34. (the 11/34 has only quad and duel
height slots left, which is why I ask...)

Thanx

Billy D'Augustine
Azog-Thoth@cup.portal.com

terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr) (12/23/90)

In article <37169@cup.portal.com>, Azog-Thoth@cup.portal.com (William Thomas Daugustine) writes:
> 
> How does one tell the difference between a Qbuss module and a Unibuss
> module? Physcally, that is. Ive never had the pleasure of working on
> Qbuss stuff, and have a memory card that I dont quite know what is.

  Well, you could look for the grant lines on the connector. Unibus boards
normally have either 4 sets of 2 fingers wired together, or an interrupt
priority plug.

  On DEC modules, the Q-bus stuff is normally named xxV11 or xxQ11, while
the Unibus stuff is xx11 or xxU11.

  Having said all that, there isn't a lot of dual-width Unibus stuff. Most
of it is either bus cables/terminators/bootstraps or boards for dedicated
slots in special backplanes. Thus I think you have a Q-bus board.

  If you want an MS11-LD (128Kw parity) or MS11-MB (128Kw ECC), drop me a
message and we'll arrange a time for you to pick it up. It should fit in
whatever mode of transportation you use 8-). Since it's all the memory
a '34 can address, you can just pull whatever boards you have in the '34
out and not worry about slots.

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, US
	terry@spcvxa.spc.edu	(201) 915-9381