KA650 in MicroVAX II BA123?

From: Chuck McManis <cmcmanis_at_mcmanis.com>
Date: Sat Nov 4 20:49:48 2000

At 08:48 PM 11/4/00 -0500, Allison wrote:
>Yes and the 3200, 3400 and 3600 seris VAXes had what cpus?

3200 - KA650
3400 - KA640 (also the 3300)
3600 - KA650 (also the 3500)

>Hint the KA650 was not a upgrade only cpu, it happens that it's Qbus
>and fits in any BAxx3 box.

The important point here is that in a BA23 or a BA123 only the KA630,
KA650, and KA655 CPUs will work with the existing cabinet kit (console port
connection etc). The KA640 and the KA660 are both constrained to living in
BA2xx or BA4xx chassis since there wasn't a cab kit that would mount on the
BA23 or BA123 plates. In terms of performance they rank
         KA630, KA640/KA650, KA655, KA660

However the KA640 has an on-board DSSI interface that gets 4MB/sec to the
drives vs the Q-bus interface on the KA630, KA650, and KA655. The KA660
also has DSSI on the CPU card.

The MicroVAX 3300/3400 were the same machine in different cabinets, the
BA215 (narrow) and BA213 (wide). I've also seen them badged VAXServer 3300
or VAXServer 3400. The MicroVAX 3500 and 3600 only came in the BA213
primarily because without an on-board ethernet or disk interface, you were
stuck using at least two slots for a DESQA and a KFQSA leaving you only 4
slots for the CPU + Memory + anything else. The MicroVAX 3800 and 3900 used
the KA655 CPU to achieve somewhat better performance however the VAX
4000/200 in the same cabinet was faster still and had the advantage of the
on-board DSSI for better disk throughput.

--Chuck
Received on Sat Nov 04 2000 - 20:49:48 GMT