[Info-vax] OT: About Digital and divisions

[ChrisQ]

On 11/23/11 18:37, Paul Sture wrote:
> On Wed, 23 Nov 2011 15:25:23 +0000, ChrisQ wrote:

>>
>> Nearly all the companies I worked with used 3rd party drives and
>> controllers, as well as analog / digital and specialist comms cards. It
>> was a thriving ecosystem, because the dec kit was so much more expensive
>> and in many cases, no better quality or reliability. The most common
>> disk setup would be fujitsu smd drives with either Dilog or more
>> commonly, Emulex disk controllers, on unibus or qbus. Emulex were and
>> are a first class engineering company and still in business,
>> whereas many of the others faded into obscurity in later years...
>>
>
> Does anyone remember Emulex CS-32 terminal controllers?  These took the
> interrupts associated with DZ-11s off the system, and IIRC you only
> needed one slot to support 32 lines.
>

I remember the Emulex comms cards. Never saw the 32 line version, but 
vaguely
remember the CS-08 and CS-16, which were the 8 and 16 line versions. I 
don't
think they were DL11 emulation, which did generate an interrupt per 
char, but
more likely a CXA16 style emulation, which had on board fifo and pre
processing. May even have some of those cards in store, though sold off 
/ gave
away much of the collected dec kit some years ago. The Emulex dual smd 
controllers
were quite a work of art. The QD32/33 did mscp emulation in only a dual 
height
qbus card and a couple of dozen chips, whereas the kda50 was two quad 
height
boards with hundreds of chips and lots of amps from the psu. Worked in 
microvax
and pdp and you could hang 2 x 8" fujitsu 2 Gbyte (2382 ?) drives on a 
single
controller, which was quite a lot of storage at the time. Coming 
originally from
a hardware background, I couldn't help but respect the skill in getting 
so much
functionality in such a small footprint and their prowess with custom 
microcircuits,
which did most of the work on the cards.
I
The setup was quite interesting, in that you had to load the drive 
format and bad
block utilities from the controller firmware via a short hand entered 
assembler
program, which then dma'd the utilities into main memory. Looking back 
it seems
a bit tortuous, but pretty standard stuff at the time.

The problem with dec wasn't just the cost, but functionality gaps which 
were quick to
be filled by the third party vendors. Viking dual height scsi 
controllers were
another example, one of which emulated mscp and tmscp -> scsi on the 
same dual height
qbus card. Part number was the qdt, iirc, with the disk only version 
being the qd0.
Rocking horse material now and very expensive, even if you can find one.

This should probably be on afc, but hey :-)...

Regards,

Chris