Josh Dersch wrote:
I understand it's possible to upgrade the backplane to 22 bits -- how is
this done?
I have a VT103 (with cards), and a funky rackmount cage with three
separate Qbus backplanes in it (thanks Phil!) that may only be 18 bit.
A while back I grabbed a number of bare Q22 backplanes off of eBay in
case I found I needed to replace the backplanes on these systems.
Haven't gotten around to even assessing feasibility, but the plan is to
try and just swap the backplanes whole. I've got a handful of KDJ11-A
dual-height CPUs to use if that works, though I'll probably need some
MXV11's or something to go with them.
The bigger question, to my mind, is how to cheaply attach disks. With
the VT103 I believe some folks have placed small disks (3.5"?) under the
CRT, where the TU58 drives would have been on a PDT-11/130. But you
still need a drive interface to talk to 'em. Perhaps one of the
Micropolis half-height ESDI drives would fit, and work with your controller.
In addition I see two projects out there for Qbus disk interfaces:
wintersweet:
http://www.mscpscsi.com/
CHD's Q22-ATA:
http://www.chd.dyndns.org/qbus_ide/
No further information, like availability or compatibility, and no
timeline for when I'll drag out the stuff I have and start contributing
... ;^)
--S.