MicroVax II

Glen Slick glen.slick at gmail.com
Tue Aug 2 22:14:06 CDT 2016

On Aug 2, 2016 7:50 PM, "Douglas Taylor" <dj.taylor4 at comcast.net> wrote:
> I had 3 different types of SCSI CDROM's and none of them worked, they are
DEC RRD42, Toshiba and a Sony.
> The DEC was dead, removed the drive and applied power that I know is good
(from a PC power supply in a working PC)
> and nothing, no led, nothing.  The toshibas would spit the caddy back out
after a few moments and the Sony
> refused to eject the caddy.
> Is there a SCSI CDROM to look for?
> I'm curious about the 68 pin scsi drives, what type do you use?  The
adapter, I guess it is 50 pin male to 68 pin male?
> Doug

I have had good luck with Plextor SCSI CD-ROM drives. I picked up some old
Plextor 4x, 6x, 8x caddy drives for a couple bucks each a RE-PC Seattle a
while ago. They have a 512-byte block mode jumper you need to set.

I got a box of 25+ IBM DDRS-39130 9GB 68-pin SCSI hard drives cheap from
someone on Craigslist a while back and have been using those with 50-pin
male / 68-pin male adapters. Only issue is that the Emulex UC07 firmware is
incompatible with them. The drives have a mode page that the UC07 doesn't
understand and it tries to do a mode select with some invalid bits for that
page, which fails. Then it keeps retrying that failure forever. No problem
with the CMD and Dilog controllers.

I often use the SG3utils sg_format utility to soft resize the 9GB drives
down to something smaller. 9GB might make sense on a VAX, not so much on a
PDP-11. Also, the built in SCSI on a VAX 3100 doesn't support drives over

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