MicroVAX II - TK50 problem

[Witchy]

> No.  It's only the RQDX1 that has the "must be last on the bus"
> problem, and only then if what's below it uses DMA  and interrupts.
>  RQDX2 and RQDX3 have no such limitation.  You won't find an RQDX1 in a
> MicroVAX II because it is not compatible with the MicroVAX II
> processor.

I know of the incompatibility but I'm surprised at the RQDX3 not having
the limitation - every single microPDP and qbus uVAX I used, installed or
watched Failed Circus maintain had to have the disk controller last on the
bus; the only exception to this was if you had the RQDXE extender for
external drives. Even the machines I've got here now are built like that.

> of any offhand that won't work in a Q22-CD slot but that doesn't mean
> there aren't any).  The MicroVAX II Micronotes actually show such a
> configuration, with a processor, single memory card, a DEQNA, an RQDX2,
> and a DHV11 (with the DHV11 last, as usual).

The only definition I've seen is that Q22/CD boards are the 'S-handle'
types for the BA4xx (and some BA2xx) and non-CD boards need to either have
jumpers removed (KDA50 springs to mind) or etches cut.

cheers,

-- 
adrian/witchy
Binary Dinosaurs creator/curator
www.binarydinosaurs.co.uk - the UKs biggest home computer collection?