DEC VT05 with OS/8 -- basic system rebuild?
ethan.dicks at gmail.com
Wed May 13 00:14:06 CDT 2009
On Wed, May 13, 2009 at 12:25 AM, Philipp Hachtmann <hachti at hachti.de> wrote:
>> I'd say this was a pretty esoteric issue. ;) I've done tons of stuff
>> with OS/8, going back to when I was about 16 (24 years ago, ugh!) but have
>> never run across this.
> Perhaps you never wanted to connect a VT05 needing fill characters to your
> system? *g*
In all honesty, no. I don't think I've ever even *seen* a VT05. I've
seen plenty of ASR-33s and lots of VT52s (and plenty more newer
terminals), just not the VT05.
In my experience, if you had an older system (pre-OMNIBUS), an ASR-33
was quite common, though I have used a VT220 with my TTL-era PDP-8s
(because of the included 20mA interface). By the time the OMNIBUS
came around (1972?), the ASR-33 was no longer the "only" terminal to
use - I've seen a number of -8/e and -8/m with either a VT52 or some
flavor of Tektronix terminal on them. The VT52 was quite common on
the PDP-8/a, and I'd say the ASR-33 much less so, but by no means
In all of that, the VT05 kinda stands apart. I don't have much
experience with the multi-terminal Edusystems, but perhaps that was a
place where the VT05 might have been used. You'd at least have a
place for a driver, unlike at the OS/8 prompt. I also don't recall
the VT05 being pushed in the PDP-8 literature of the day, unlike the
ASR-33 and the VT52.
>> Now, I finally got an ASR-33 a few weeks ago, and I want to connect it to
>> a PDP-8, so I might have to think about this some more! :)
> You won't need to think too much: ASR33 simply works out of the box. Insert
> a KL8-E board, hook up the ASR33, run OS/8.
As long as you have the DEC reader-run-relay mod (there'll be a 6-wire
cable from the TTY, not 4-wire), you'll do great. If you lack the
RRR, you will probably have issues trying to load software, but you
can punch tape and run software from the keyboard and printer just
fine. There are plenty of 4-wire ASR-33s out there from DEC
installations because they were used for non-console use, say on an
DZ11 or a KL8JA. If you lack the RRR mod, I know I've seen it at the
back of one of the DEC print sets, though I can't recall right now if
it was a PDP-8 print set or an 11/20 printset (I have both and have
read both many times).
If your ASR-33 hasn't been cleaned and properly lubed (not
over-lubed), you might want to take some time cleaning and adjusting
it. I know I have to tweak on mine once or twice a year, but nothing
really major - just make sure the top and bottom of the letters make
even impressions, make sure the keys all create letters (and send bits
down the wire). It shouldn't be hard to locate or write an ASCII echo
program for testing the TTY. It's much more revealing of problems
than trying to type DIR commands in OS/8.
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