MicroVAX 4000-105 Fast Wide Differential option?

[Zane H. Healy]

> Today I came across an oddity, a standard ds-47dbm-b9 VAX 4000-105A but
> seemingly featuring a third-party FWD/DSSI/SCSI option. Instead of the usual
> angled rear connector box containing 2 DSSI busses and a SCSI-1 connector
> the machine had a rectangular breakout box that featured from top to bottom
> FWD SCSI (68pin), blank, DSSI (single port), SCSI-1. The FWD port was
> connected to a Baydel RAIDER5 raid system and also had a differential
> terminator.
> 
> I'm pretty sure that wasn't a DEC option in the UK, 2 DEC resellers I know
> agree so has anyone else heard of this? I wasn't allowed to shut the machine
> down so I couldn't check for manufacturers or part numbers..... VMS
> designator for the drive was DKW100 which further points at it being wide
> SCSI....
> 
> cheers!
> 
> adrian/witchy

My first thought would be that it's a 90's era upgrade from Nemonix as I
believe they did (and still do) most of the VAX 4000 upgrades.
 http://www.nemonixengineering.com/

Zane