TTY 33 - Finally

william degnan billdegnan at
Fri Jul 3 21:00:19 CDT 2015

Sometimes holding the reader clip down with a bit of pressure will help.

On Fri, Jul 3, 2015 at 9:59 PM, william degnan <billdegnan at> wrote:

> It may be the that the reader clip is not in the correct position.   What
> happens when you push down the blick relay switch in the back that moves
> the reader.  It's the flat, oddly-shaped piece of metal next to the where
> the yellow and blown wires attach from the UCC-6
> If you quickly press this switch, does the reader advance once (or hold it
> down to run the reader.
> It also may be that you have a crossed bar inside of the reader.
> Start with that let us know what you find.
> Bill
> On Fri, Jul 3, 2015 at 9:50 PM, Rick Bensene <rickb at> wrote:
>> Hello, all,
>> Today I received a very nice, (mostly) operational Teletype ASR-33.  It
>> is in really stunning cracks, very little discoloring,
>> everything is there, and the best part is that it is very clean inside, and
>> it works great as far as I can test it in local mode, except for one thing:
>> The paper tape reader has a problem.  Put a tape in, clip down the cover
>> (not this is all done in LOCAL mode), and press the lever to START, and the
>> tape reads one frame, prints the character, the reader stops, and the
>> printer acts like it is receiving a BREAK signal...just free-runs without
>> printing anything more.  Only way to stop it is to power it off, then power
>> it back on again.
>> I know there is the Green Keys list, but I'm not a member (though I
>> probably should be now), but knowing the knowledge base of folks on this
>> list, I figured I'd ask here first, and see if anyone has any ideas.
>> The TTY came with a neat General Electric TDM-114 Acoustically Coupled
>> Data Set.  There's a cable that comes out of the terminal (it's a table top
>> model, not a pedestal model) that has a six-pin connector that plugs into a
>> socket  on the back of the dataset.   The acoustic coupler cups aren't very
>> deep, and are a relatively hard rubber-like material, but there are little
>> spring loaded rollers that are designed to grab onto the handset and press
>> it securely against the coupler cups.  Quite different from many of the
>> pressure-fit acoustic couplers that I've seen.   This one requires the use
>> of on original-style Western Electric telephone...anything else won't latch
>> into the coupler.  Fortunately, I've got a few of the old Western Electric
>> telephone sets around here so I can test it out.     Not much information
>> out there about this modem...when I get it working, I'll have to take some
>> pix and maybe a video of it running with the terminal, and post a little
>> video about it on YouTube.
>> I'm wondering if perhaps TTL or (I'd never get so lucky) RS-232 signals
>> are used for the coupler.  I haven't taken the cover off the unit yet to
>> determine if how the cable is connected into the terminal, as I'm really
>> itching to hook this thing up to my PDP 8/e and do some "period-correct"
>> computing.   If the terminal only does current-loop, I think that I can
>> make a cable that'll work with the serial card in the 8/e to get the
>> terminal going (I seem to remember the serial card (can't remember the M
>> number) can do both current loop and RS-232), but if the TTY could easily
>> do RS-232, then it'd be a snap to hook it up.
>> Last week I did order a nice little Black Box Current Loop to RS-232
>> converter, which will make things easier, but it'll be a few days before it
>> gets here.
>> Fortunately, the TTY also came with original Teletype technical docs, so
>> once I get it open, I should be pretty easily able to figure things out.
>> Along with the TTY, also came two TI Silent 700 780-series data terminals
>> and an old TI calculator for the museum.
>> Anyway, I'm really happy to have finally after so many years to have got
>> my hands on a trusty old Teletype ASR-33.
>> Happy Independence Day to all!
>> Rick Bensene
>> The Old Calculator Museum

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