On Mon, Dec 29, 2003 at 08:39:17AM -0600, Jay West wrote:
> Ethan wrote....
> > I have run 2.9BSD on an 11/24 w/3MB of memory and two RL02s...
At the time, I didn't own a Split I&D machine (I have an 11/44 that's
awaiting my attention when I return, as well as a pair of 11/70s). Also,
way back when (c. 1987), I only had a couple of magtapes with 2.9BSD.
These days, of course, all of that stuff is easier to get than it once
was. The trick is what one can do with lower-end equipment. With 10MB
disks, the answer is, not much. :-( Even a 28MB disk would have helped
immeasurably.
> I'm jealous - I still want an 11/750 or 11/780, but I KNOW I don't have room
> for that right now.
The 11/780 is a monster, but the 11/750 is not so bad at all. We used to
put the console on top, saving some space there, plus, with some sort of
5.25" disk (SMD/ESDI/RA7x), there's room inside the box for a disk as well
(I'd use a seperate power supply though). In one cabinet, you can have
the CPU, 8MB (or 14MB if you are lucky), a terminal controller or two
(Emulex CS21, DZ11, DMF32...), a UDA-50 or Emulex disk interface, a line
printer interface (LP11 or DMF-32)... in short... everything you really need
inside the cab. We didn't do it that way in the old days, only because the
disks wouldn't fit.
> Oh really! I didn't think of that. I have a boatload (maybe 6 or 7) RA81's.
> If I can find a UDA-50, RA81 it is!
That will be *plenty* of room for 2.11BSD.
> Thanks for the tip!
Sure thing. I just wish Unibus SCSI interfaces were cheap and plentiful.
Every once in a while, I kick around the idea of modding a COMBOARD into
a SCSI card, but then the urge subsides and I get back to more productive
pursuits. One thing that holds me back is that there's no practical way
to turn a COMBOARD into a *compatible* Unibus interface. I could use the
68000 on-board to talk to a Z5380 chip or a WD33C93 or the like (and
borrow the SCSI code from a variety of sources, like the Amiga), but
there's no way to make the COMBOARD's registers resemble anything like an
MSCP controller or old-fashioned SMD/ESDI controller.
With Digital's patent's on MSCP expired or nearly so, I wonder what it would
take to build a converter to attach to a UDA-50/KDA-50/KDB-50... The interface
chips and cables could be scavenged from a dead RA81, but I have no idea
what it would take to build a box that spoke SCSI or IDE out one end, and
SDI out the other... any takers? It might be easier than the ST506 converter
we've been discussing. At least in this case, it's digital in and out, with
no sampling required.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 29-Dec-2003 15:51 Z
South Pole Station
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Ethan.Dicks_at_amanda.spole.gov http://penguincentral.com/penguincentral.html
Received on Mon Dec 29 2003 - 10:00:53 GMT