At 09:38 AM 1/21/02, John Maier wrote:
>Ok...that's very cool to know...but then if things couldn't get worse...I 
>see this KA640
>on ebay...I get currious...
>
>So where does this fall into the picture!
>
>I'm slowly picking together how Qbus-VAX works...

The KA640 has the same CPU bulkhead connection as that KA660 so a cabinet 
kit that works with the KA640 will also work with the KA660.

KA630   - "Dual cable" bulkhead, one is the serial console
           and one is the LED display + baudrate + mode select

This bulkhead was also used by the KA650 (MicroVAX III, MicroVAX 
3500/3600), KA655 (MicroVAX 3800/3900) In the case of the 
3500/3600/3800/3900 there is a cabinet bulkhead for the BA213 style chassis 
that is full length, has an MMJ connector and the LED display on the front 
plus a console "mode" switch. (see 
<http://www.mcmanis.com/chuck/computers/vaxen/panels.html>)

KA640   - "Single cable" bulkhead, originally BA213 type only,
            has a single ribbon cable that connects not only
            the console stuff but also carries the signals for
            an on-board Ethernet interface.

            There is a separate 50 pin connector for DSSI next
            to the memory connector.

This bulkhead was used in the MicroVAX 3300/3400, and then later in the VAX 
4000/200 (KA660). Apparently there was enough demand by people to upgrade 
their older BA23/BA123 systems to the KA660 that a variant was produced 
that brought the single cable out to two "plates" one plate is the CPU 
console connection, and the other is the ethernet AUI connector.

Another innovation on the KA660 was the routing of the DSSI signals to the 
"unused" side of the C/D connectors which allows the KA660 to connect to 
the internal drives in the BA440 without an additional cable. In the BA213 
chassis a separate cable snakes up from the CPU card to the drives in the top.

--Chuck