10 Apr
2012
10 Apr
'12
5:32 a.m.
On Apr 10, 2012, at 12:33 AM, Cameron Kaiser wrote:
Depends on what you want to do with it. I have a CQD-220 MSCP SCSI card
(which I highly recommend) which will support SCSI disks on any operating
system that supports MSCP (later versions of everything DEC, and I believe
someone has working MSCP patched into 2.9BSD which is the last that'll run
on a /23 due to the lack of split I/D). I also have a TSV-05 system (DEC
Pertec controller and DEC-branded Cipher-F880 9-track tape drive, which
is larger than the machine it's talking to). And I landed a DELQA (good
Ethernet controller, ironically running on a 10MHz 68000 which is
probably faster than the /23 it's running in), which will be useful once
I get my act together to get something running with it.
I'd say hunt for a good MSCP controller of some sort first; the SCSI cards
are a great deal if you're into old Macs and have lots of older SCSI disks
lying about. :-) It's not as simple to bootstrap something onto it,
though, not nearly as much as the tape drive. I wrote a quick assembly
bootstrap and corresponding Python script to load and execute programs
over the serial port so I could e.g. write tapes out and boot from them,
but MSCP is a much more complex protocol and I'm more interested in
letting the OS handle that for the time being.
I know lots of people like to do emulated TU58s (DECTapes) over the serial
port. I haven't done that yet. As Ethan mentioned above, the 11/23+ has
the serial ports built in - that's the one I have. Nice, all-in-one quad-
size CPU board with serial and bootstrap... no fuss, no muss. :-) Of
course, the built-in serial only goes up to 19200 baud, which means
writing out a full 40MB 1600bpi tape takes... a while.
- Dave
Try an 11/23.
That's what I've got, and I run the backplane off a
hacked-up AT power supply tied to the rails. One of these days, when
I find one in good condition, it'll go in a BA11 or BA23 (though if I
find a good BA23, I'll probably try to find something beefier to go
in it).
For now, though, it's pretty content in its bare 4x4 backplane (about
the size of a VCR) with a decent fan blowing through it. Easy enough
to contain for most people.
How much does a "bare" 11/23 do, however? What do you use for mass storage?
(I did say I was totally ignorant of PDPs.)