Q-bus SCSI Controllers RFI

[Jerome H. Fine]

 >Zane H. Healy wrote:

> At 4:15 PM +0000 2/23/08, Martin Bishop wrote:
>
>> What I'm curious to know is:
>>
>> - What boards were made and which are commonly available
>>
>> e.g. DEC KZQSA, CMD CDQ-220, Dilog SQ706 ?, Emulex UC02 ?, Andromeda
>> SCDC-11 ?, ...
>>
>> - The relative (to SCSI 1) performance of each of the boards
>>
>> - Which boards are "dogs" : gotchas, tape only, unreliability /
>> electronics failures
>
>
> The Viking QDT (disk/tape also available as tape or disk only) aren't 
> the fastest boards out there (I think those are the CMD boards), but 
> they're good rock solid boards.  With the most recent versions of 
> firmware they should work good with a CD-ROM.  While I use mine in 
> PDP-11's, I'm thinking about putting one in a MicroVAX III (I want to 
> move off RA72's and RA73's).  I typically have Seagate 2GB 
> Barracuda's, a Plextor 8x CD-ROM, and either a TZ30 or TLZ06 (4mm) 
> attached.  I've also used a 2x DEC CD-ROM, and IBM 100Mb and 200MB 
> SCSI drives in the past.

Jerome Fine replies:

I have never found a CDROM that was usable - never tried that hard.

I have had good experience for disk drives with the CQD-220/TM
and a friend of mine with the UC07 (if I remember the number - I
don't think it was the UC02, but I could be wrong).

The Dilog SQ706A did not work, but that was 15 years ago when
it was brand new and there was a firmware bug - which Dilog
knew about, but would not fix promptly enough to use.  Actually
the CQD220/TM had the same firmware problem, but I had a fixed
working EPROM with the revised firmware in 2 weeks!  In both
cases, the bug was a buffer which overlapped a 256 KByte boundary
in physical memory on the Qbus.  Since my test program used
6 * 24 KByte buffers, there was a high probability that one
buffer would overlap a 256 KByte boundary.

Sincerely yours,

Jerome Fine
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