rewriting legacy OS for new iron

From: Zane H. Healy <healyzh_at_aracnet.com>
Date: Tue Sep 14 18:26:45 2004

> you might as well consider a Qbus SCSI card. Best to stay away from RD53s
> (Micropolis 1355 w/R7 jumper added) unless you a) have a good backup scheme,
> and b) like replacing drives every few years.

If it's only every few years you've had far better luck than me. The
longest I've been able to keep an RD53 running was about 3 days.

> (KDJ-11 CPU) to be a bit better, not even counting the fact that you get
> Split I&D space and can build larger programs. Yes, an 11/73 or /83
> would be 'snappier', but a bit more pricey, especially over an 11/23.

As long as you don't mind dealing with the troubles involved in a
dual-height /73 CPU, they aren't to hard to come by. Of course if you do
get one you'll want a third party disk controller w/bootstrap, and a DLV11J
for your console ports. It's a pain, but it works. Until I upgraded to a
Quad-Height /73 CPU, I kept a Webster ESDI board in the system for the
bootstrap even though it didn't have any disks attached and the system disk
was on a SCSI controller.

> I would love to find an 11/8x or 11/9x, but I'm not holding my breath. At

Ditto. Actually what I *really* want is one of the newer Mentec CPU boards!

> the moment, my fastest real Qbus -11 CPU is out of a communications server,
> making it, ISTR, the same as an 11/53 CPU (with different ROMs, but I
> have solved that already). It is destined to go into a BA123, perhaps with
> a 3rd party disk controller.

Let me guess it's out of a DECserver 550, if so it's a /53.

                Zane
Received on Tue Sep 14 2004 - 18:26:45 BST