Subject: Re: SCSI on Q-bus
To: None <port-vax@NetBSD.ORG>
From: Chris Quayle <icq@dial.pipex.com>
List: port-vax
Date: 02/05/1998 19:43:51
Hi,

Finally found it - after much searching in the loft...

There is a dec qbus handbook entitled "pdp11 bus handbook" Dec part
number EB 17525, published 1979. Had two copies of this but must have
lent one out at some time as can only find the one copy now.

The interface is actually quite simple, (aka Intel multiplexed address /
data bus etc) - had to build a qbus rom emulator some years ago and
istr, we used one of the blank dec qbus prototyping cards for the job -
loads of wirewrap etc. We also used the dec DCxxx series chips from
digital to implement the bus protocol, though don't know if these would
still be available from dec. If not, probably best to use a Xilinx gate
array or whatever to do the protocol and HCmos or ls ttl for the rest.
Not a five minute design job if you want to run dma though...

Let me know if you want the book copying - would think dec are too busy
thinking about the impending doom of PomQuak to worry about the
copyright...

Regards, Chris


emanuel stiebler wrote:
> 
> Hi all,
> 
> what is a "realistic" price for a Q-bus SCSI controller supperted by NetBSD
> ?
> Looks like i'm the only one who hasn't one. But i have something about 10
> SCSI disks here.
> I e-mailed DILOG, but the price of 1700 $ is more than i like to spend.
> (more than 1500 to much...)
> 
> What makes this scsi so expensive ?
> Is there a patent on this MSCP, TMSCP protocols ?
> 
> I'm thinking about developing one for the q-bus, should be cheaper than
> .., and i could use my disks here.
> (its not my first one, i build such stuff on vme-bus before)
> 
> thanks,
> emanuel