[Info-vax] coming soon: old DEC hardware free to a good home

[Antonio Carlini]

On 25 Sep 2009, someone wrote in comp.os.vms:

.
> 
> Just to add some detail to the above answer.
> The 3100 series was called MicroVAX, but the 4100 series was called VAX 
> 4000 model 100 (or 100A, 105A, 106A and 108).
> The main system board was indeed the same on some models of MicroVAX 
> 3100 and VAX 4000-10*.
> And like earlier said, the main difference between the two model series 
>   was two SCSI buses on MicroVAX and two DSSI buses on VAX 4000-10*. The 
> VAX 4000-10* had also a SCSI bus.

The KA50 and KA52 (I may have those numbers wrong :-)) were indeed the same
motherboard. More than that, with a simple command you could reflash either
into its evil twin.

That made a difference (IIRC) to licencing.

I don't recall whether the DSSI interface or the Qbus adapter worked in
both modes or just the one. They may have been addon boards internally
anyway (so you may not have one or the other).

Antonio