> I still didn't have the guts to try and disassemble the typing unit
> or the keyboard, but with access to their undersides, I was able to
Puty, becaue it really isn't that hard. If i could do it without the
manuals and without this list while still at school, then you can do it
now :-)
> problems remained, no line feed and no bell. I took the typing unit
> back out and looked carefully at the area of the line feed mechanism.
> It was substantially different from the illustrations in the documents.
Do you have the partsbook? I find it to be one of the most useful manuals
for the Model 33 becuase of all the exploded diagrams. Anyway, the
partsbook I have shows 2 different versions of the friction-feed platten
mechanism. The older one has ratchet teeth at both ends of the platten,
the later one only at the left side.
[..]
> The punch seemed like it would be almost trivial. It was, _almost_. The
> punch essentially just bolts onto the side of the typing unit. There are
> eight small levers that control which holes are punched and there is a
> large lever that provides the "power". The small levers simply drop into
> place, connecting with push rods in the typing unit. The large lever
> connects to a rotating shaft in the typing unit. Here's where the trick is.
> The lever connects to the shaft via a sleeve. The shaft has holes all the
> way through it, the sleeve has holes on both sides and screws go all the
> way through the sleeve and the shaft. There is almost no play in the
> connection... almost. I took out the KSR typing unit and transferred the
> punch mechanism to it.
>
> I put the KSR typing unit back in, threaded in some tape and tried it.
> Shredded
> tape. What??? Everything sure looked OK. The "bit" levers looked like
> they were all moving correctly, the large lever seemed to be going through
> its motions. I spent a long time watching it. Finally, I tried putting it
> back on the ASR typing unit. Shredded tape. WHAT!!! What could possibly
> have changed? Maybe I attached the sleeve for the large lever to the wrong
> holes? No, those are the only holes in the shaft. That's when I noticed
> that little bit of play. Just three or four degrees. That couldn't
> possibly make any difference, could it? I held the play all the way
> clockwise
> and tightened the sleeve screws. Shredded tape. I loosened up the sleeve,
> held the play all the way counter-clockwise and retightened. Perfect! I
> moved the punch back to the KSR typing unit and, with my new knowledge, got
> it attached and working.
That link is actually in 2 parts -- the sleeve that clamps to the shaft
and the crank plate that carries the link to the punch. They re held
together by a screw. Loosening that gives you quite a bit of adjustment
(10's of degrees)(, and that's waht you should be using.
>
> After the punch experience, I spent a very long taking exact measurements of
> the reader control mechanism that needed to be moved to the KSR typing unit.
> It is a complicated little assembly, consisting of a cam controlled lever
> that moves based on whether a solenoid is energized and in turn opens and
> closes a switch as the cam rotates. It looked like the location tolerances
> of the whole thing would be about a sixteenth of an inch. There is a spring
> that attaches to the lever and keeps it pressed tight against the cam. I
> transferred the mechanism. Attaching the spring turned out to be the
> hardest
> part of the whole job. The lever end of the spring is "permanently"
It's a lot easier if you remove the transmitter shaft first. Take the
distributoir unit apart, then unto the clamps over the bearings and
essentailly the shaft justlifts out.
> attached,
> but the other end has to thread through a tight space and hook over a small
> pin that is part of the typing unit frame. I fooled with it for more than
> an
> hour. What finally worked was to tie some plastic fishing line to the end
> of
> the spring, guide the line to the pin and use the line to stretch the spring
> over to the pin. I used a piece of "coat hanger" wire to coax the loop at
> the
> end of the spring over the pin and then finally reached in with a long thin
> scalpel to cut the line and pull it out.
Many years ago I bought a set of speing hooks spedifically for doing
things like this. They weren't cheap, but they've saved a lot of bad
lanugage over the years :-)
>
> "There's the easy part done," I said to myself. I figured I would spend the
> rest of the day getting the lever, solenoid and switch lined up correctly.
> I put the KSR... well, now it was really the ASR, typing unit back in and
> fired it up. The bit gods, or maybe Rube Goldberg himself, smiled upon me.
> It worked the first time.
Actually, I've never hand any problems getting that part to work first
time...
-tony
> I should point out here that, while I'm not bothered by the complexity
> of electronic circuits, I find mechanical complexity (lots of levers,
> gears, cogs and the like) a bit intimidating.
I guess I had a mis-spent childhood. I grew up taking mechanicla things
apart, and more importantly putting them together again. When I got my
first ASR33 (back in 1985 I think), I didn't have the maniuals, there
were no mailing lists like this (at least not in the UK), but I still,
very carefully, took it apart, right down to the last nut and bolt. And
then put it together again.
I would like to say it worked first time, but that would be a lie. No,
I'd mis-assembled the feed-supression linkage so that it moved the
carriage on control codes. But it didn't take me too long to figure htat
out too.
-tony
Thanks to Pete Turnbull's FindCSR (entering it once by hand was
enough) :) and reading another manufacturer's DHV11/16 documentation
dug up on Bitsavers, I now know my CSR.
Actually, two of them, 160140 and 160160, since I have learned that a
DHV11/16 appears to the 11/23+ as two DHV11 8-line cards with
consecutive address spaces modulo 20 octal.
Then I could run the various DHV11 diagnostics from my XXDP pack, and
the first time through on VDHAE0, it found the card but stopped on an
ILL INT 430 error. So I took the hint and entered 430 instead of the
default 300 for the vector interrupt address. Then Unit 1 passed the
tests, but Unit 2 had an ILL INT 440 error. Another clue :) With 440
for the 2nd vector it passed all tests.
Now to make sure it's not conflicting with my RLV12 controller, make a
cable for the user terminal, and start fumbling with TSGEN.MAC and
other TSX-Plus files!
All I need is a few VT100's and this will be 100% identical to the
system I used at my first EE job (in 1981) :)
-Charles
dwight elvey wrote:
> I needed to make a little more space and guess
> what I found in the box for the stand. you guessed
> it, the supply board for the tape reader.
That is the same way mine is configured. I think it
is using the whole stand as a heat sink.
> The H plate is easy to do, jammed on the end of
> a screw driver blade.
Like I said, "once you get the knack".
Bill
I think the real gotcha will be the DOS drivers.
The 802.11b DOS driver+hardware combo I know about is PCMCIA. ORiNOCO Gold is PCMCIA, has MS-DOS drivers, has 128 bit WEP and was a highly respected card when it was new.
PCMCIA card to ISA slot ... I remember some bridges that have Windows 95 or Windows NT drivers for the bridge itself. It's not pretty.
Tim.
For fun, I'd like to mix old with slightly-less-old and put an 802.11
wireless card in my old Compaq 386 luggable. Does anyone know if
there is a card that is both ISA and has DOS drivers? Doing WEP would
be a bonus, 128-bit WEP more so. If no WEP, I can set up a separate
AP for it but it would be nice to take it on the road (being a
"portable" and all.)
The Cisco AIR-ISA34x series seem to fit the bill. One chart I found:
http://www.kmj.com/cisco/340a.html
...suggests that the ISA342 will do 128-bit WEP. so maybe that is the
one to find.
Any other ideas/suggestions/experience?
-j
--
silent700.blogspot.com
Retrocomputing and collecting in the Chicago area:
http://chiclassiccomp.org
_Teletype_Tales_
Part 3 - How I Spent My Christmas Vacation
If you're still reading, don't worry, this is the last part...
but it is a bit long.
This year I ended up with a good chunk of "left over" vacation
time. My employer implemented a "use or lose" vacation policy
and my boss, a _really_ nice guy, was insistent that none of his
staff was going to lose any. So I ended up on vacation for the
last two weeks of 2010 despite having a rather heavy feature
request list on my plate. What to do? Spend a lot of time with
my family of course but after a discussion with my wife it was
decided that part of my Christmas present would be several
uninterrupted days of hobby time. Time to "bite the bullet" and
get that teletype working. Or end up with a big pile of levers,
cams, spring, cogs, etc.
The day came and I jumped in with both feet. I took a few pictures
and made a few notes. Then I pulled all of the cables off of the
call control unit, popped out the h-plate and lifted the typing
unit out. I guess I half expected springs and gears to go flying
everywhere but it came out neat and easy. Even after all of the
work I had done before, the filth was incredible. In addition to
much more dog hair and bug bits, there was oil soaked chad and this
"goop" everywhere. But now I could see the source of the goop.
Under the typing unit, there was what had been a large foam rubber
pad. It had decayed into crumbly dust that, when exposed to oil,
turned into the goop. Clearly, more cleaning was required. Do
another halfway job? Nope, take it all the way apart. Four screws
later and the call control unit lifted out. Two more after that and
the keyboard was free. One last screw and the tape reader was out.
Now I could fully clean the subbase. Lots of detergent, warm water,
gentle scrubbing and, finally, paper towels and it was squeaky clean.
I still didn't have the guts to try and disassemble the typing unit
or the keyboard, but with access to their undersides, I was able to
clean a lot more gunk out of them with a combination of light
instrument oil, canned air, paint brushes and toothpicks. Well, that
had to be a good bit better.
I put it all back together. Getting the h-plate back in isn't too hard
once you get the knack. Plug in, local mode, a definite improvement.
The carriage movement wasn't perfect but it was much better. The
keypress encode/decode now seemed to match in almost all cases. Two
problems remained, no line feed and no bell. I took the typing unit
back out and looked carefully at the area of the line feed mechanism.
It was substantially different from the illustrations in the documents.
At this point, I made what turned out to be a great decision. I brought
out the KSR to see if its line feed mechanism looked like the docs.
The h-plate in the KSR was already out as a result of its previous
misadventures. Pulling the cables to the call control unit was easy
and I lifted out the KSR typing unit. Its line feed mechanism seemed
to match the docs. As I looked at it, I realized that it didn't seem
to be damaged in any way. I hand turned the motor a few revolutions
and everything seemed OK. I decided I would give it a try, installed
in the ASR. I spent a little while, giving it the same cleaning I
gave the ASR typing unit. One interesting "tidbit" about this typing
unit is that, sometime in its past, it clearly "ate" a ribbon. There
were bits of shredded ribbon all through it. My hands were black.
To make a long story short, the KSR typing unit worked perfectly in
the ASR, bell, line feed and all. During the test, I didn't reconnect
the reader to the call control unit because the reader control mechanism
is part of the ASR typing unit and I was concerned that the reader might
"run wild". So now I'm looking at the docs, wondering how hard it would
be to transfer the punch and reader control over to the KSR typing unit.
The punch seemed like it would be almost trivial. It was, _almost_. The
punch essentially just bolts onto the side of the typing unit. There are
eight small levers that control which holes are punched and there is a
large lever that provides the "power". The small levers simply drop into
place, connecting with push rods in the typing unit. The large lever
connects to a rotating shaft in the typing unit. Here's where the trick is.
The lever connects to the shaft via a sleeve. The shaft has holes all the
way through it, the sleeve has holes on both sides and screws go all the
way through the sleeve and the shaft. There is almost no play in the
connection... almost. I took out the KSR typing unit and transferred the
punch mechanism to it.
I put the KSR typing unit back in, threaded in some tape and tried it.
Shredded
tape. What??? Everything sure looked OK. The "bit" levers looked like
they were all moving correctly, the large lever seemed to be going through
its motions. I spent a long time watching it. Finally, I tried putting it
back on the ASR typing unit. Shredded tape. WHAT!!! What could possibly
have changed? Maybe I attached the sleeve for the large lever to the wrong
holes? No, those are the only holes in the shaft. That's when I noticed
that little bit of play. Just three or four degrees. That couldn't
possibly make any difference, could it? I held the play all the way
clockwise
and tightened the sleeve screws. Shredded tape. I loosened up the sleeve,
held the play all the way counter-clockwise and retightened. Perfect! I
moved the punch back to the KSR typing unit and, with my new knowledge, got
it attached and working.
After the punch experience, I spent a very long taking exact measurements of
the reader control mechanism that needed to be moved to the KSR typing unit.
It is a complicated little assembly, consisting of a cam controlled lever
that moves based on whether a solenoid is energized and in turn opens and
closes a switch as the cam rotates. It looked like the location tolerances
of the whole thing would be about a sixteenth of an inch. There is a spring
that attaches to the lever and keeps it pressed tight against the cam. I
transferred the mechanism. Attaching the spring turned out to be the
hardest
part of the whole job. The lever end of the spring is "permanently"
attached,
but the other end has to thread through a tight space and hook over a small
pin that is part of the typing unit frame. I fooled with it for more than
an
hour. What finally worked was to tie some plastic fishing line to the end
of
the spring, guide the line to the pin and use the line to stretch the spring
over to the pin. I used a piece of "coat hanger" wire to coax the loop at
the
end of the spring over the pin and then finally reached in with a long thin
scalpel to cut the line and pull it out.
"There's the easy part done," I said to myself. I figured I would spend the
rest of the day getting the lever, solenoid and switch lined up correctly.
I put the KSR... well, now it was really the ASR, typing unit back in and
fired it up. The bit gods, or maybe Rube Goldberg himself, smiled upon me.
It worked the first time.
Now to talk to the world. I don't have anything that is currently
configured
to "talk" current loop but I have a current loop to RS-232 converter. I'll
spare you the details of frustratingly confusing documents that aren't clear
about which wire pairs the 33 is sending on and which it is receiving on,
but
I will mention that the current loop to RS-232 converter is pretty old and
populated with tantalum capacitors. Guess what caught fire? Fortunately,
B&B
publishes the schematics for the converter on the web. They also publish a
nice little document that shows how to wire up a 20ma current source for the
loop. In case you didn't look before, the pictures are here:
http://wsudbrink.dyndns.org:8080/images/teletype/
P1010006 and P1010007 show the converter and the current source, built in
an old RS-232 patch box. The pin sockets had been previously damaged, so I
removed them and soldered the circuit directly to the PC board in the patch
box. Oh, the external power connector on the RS-232 converter melted when
the caps burned, so the patch box also supplies power to the converter.
But that was it for the problems. The 33 now talks to itself perfectly in
local mode and talks to the world over the RS-232 converter. I've hooked
it up to one of my IMSAIs and to my Altair 680.
So, that's about it, the end of an almost ten year "saga". What's left?
Two things, one big but minor and one small but rather major. The big
minor thing is the back panel to the stand. It's missing, it's big, but
you can't see it unless you pull the unit away from the wall and walk around
back. Its absence doesn't seem to hurt anything and I'm not even sure the
unit originally had one as there are no scuffs or scratches where you would
expect if one had been installed. Now, the small major thing is the small
screw (Teletype part number TP183112) that holds the paper tape reader cover
in place. It is physically small, but it is major because the cover bounces
around during normal operation without it. It seems to be a rather special
screw, more like a threaded rod. If I can't get an original, I will
probably
try to fabricate one myself.
Oh, the last thing is the KSR unit. It is partially operating, no bell or
line feed and under the wrong cover. I'm going to hang on to it for spares
if anything in the ASR breaks. I guess I really lucked out in my recent
restoration. I didn't have to dig deeply into the keyboard or the typing
units... knock on wood, I can't imagine what horrors of finely tuned springs
and levers lurk in them :-).
I hope you have enjoyed reading this,
Bill Sudbrink, January 2011
_Teletype_Tales_
Part 2 - Waiting For Another Day
For ten years (Really? Ten? Well, more than nine.) the two teletypes
have sat in a corner of my basement. From time to time, I made
requests (public and private) for help, but nothing I could offer
(mostly unlimited pizza and beer) could entice anyone knowledgeable
to come give me a hand. That's not to say that no progress was made
however.
Most of the progress came in the form of further acquisitions. The
first was a nice shiny chad bin. There was a chad bin with the ASR
when I got it, but the plastic had degraded to an opaque milky yellow
and the "lip" that is supposed to hold it in place had broken off and
been lost. When I got the ASR, the bin was being held in place with
masking tape. The "new" bin is whole and crystal clear. It has just
the slightest golden tint to betray its age.
I also went to work getting original prints of all of the model 33
documentation. I got them in bits and pieces over the years, some
bought, some gifts, a single section here, a collection there. I'm
now confident that I have a complete set, in fact, I think I've ended
up with two complete sets and three copies of a few of the sections.
The best part came on Father's Day of 2002. A greenkeyer pointed me
to a shop that had some "new old stock" model 33 parts. The prices
weren't too bad and my wife agreed to let me get what they had as my
Father's Day present. They didn't have any KSR covers, but they had
a complete ASR cover, brand new, punch, reader, top cover, front metal
nameplate and mode select knob. Pictures here:
http://wsudbrink.dyndns.org:8080/images/teletype/
The P53* pictures are before installation, the P10* pictures are
installed. There are also pictures of my recent work, described in
part 3. I unscrewed the reader and punch covers from the old cover
and put that on the KSR. Better than nothing.
I made occasional attempts to further clean and lubricate the ASR,
still afraid to really take it apart. I did manage to get the carriage
to move somewhat but not really well. The punch seemed to work, punching
values that matched whatever it printed. It would punch a line feed, but
the paper wouldn't budge. It would also punch a control-G but the bell
would not ring. I never made any attempt to hook up the current loop.
Everything I did was in local mode.
End of part 2.
