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IBM PC to teltype?

Also, be aware that teletypes come in two encoding flavors, the so-called "7 level" or the ASCII-speaking one (e.g. model 33) and the "5 level" (e.g. model 35) which uses its own code.

I used an adapter from a S100 CP/M machine to a 5-level international telex machine - the code was called BAUDOT.
The adapter converted RS232 signal from a serial printer port to current loop at standard telephone line voltage. Some driver code converted ASCII text to BAUDOT output. IIRC no handshaking was used. ASCII bit 6 triggered the register shift, I think. I still have the 8-bit 8080 Assembler source for that driver, if OP or anyone else wants to run a 5-level BAUDOT telex machine from a RS232 port. Standard baud rate was 50bps - a bit less than 5 chars per second. The hardware adapter was fairly simple as I recall, but what I have left of it has been robbed of some components over the years and I don't have a schematic.

My setup was output-only. Presumably a reverse adapter for input would be equally simple.

Rick
 
Yes, I know that people call the code "Baudot", but strictly speaking, that's not what it is--the "modern" 5-level code is ITA2 and is a modification of a code called "Murray Code" which is a modification of Baudot's scheme by Donald Murray. In short, Baudot's code was made for a 5-key keyboard and one operated it by depressing various combinations of keys. The characters in Baudot's code are quite different from ITA2--and you would not recognize many of them.

Yet another misunderstanding of the word "Baudot", I suppose. I wanted to avoid the whole business of having to explain my use of "5 level", but I guess that I ended up doing it anyway.

And yes, back in the early days of hobby computers, one could, with a minor amount of software and some lookup tables, convert 7-level ASCII (other variants of ASCII do exist, but that's another story) to an ITA-2 representation. Note that ITA-2 does not have many special characters, nor does it have lowercase, so there are some compromises.

A similar setup was used when driving IBM I/O Selectric terminals, such as the 2741. Normal "golf ball" character coding uses a "rotate and tilt" code, usually called "correspondence code", which bears no resemblance to any computer code. So you could either use software or purchase a box to handle the code conversion. There were somewhat harder-to-find type balls that were used on S/360 operator's console Selectrics that had characters ordered to correspond roughly to EBCDIC. A practical joke that was sometimes played on operators and secretaries (no "administrative assistants" back in those days!) was to swap the typeball types. The units would work fine with either--but what came out was pure gibberish.

I've said too much already, sorry.
 
Thanks, I think that I now know the difference between the level 5 and 7 codes.
One more question on a modern computer (windows XP) would it be possible to control a teletype with its rs-232c port with a terminal emulator or something?
 
If the teletype has been converted to RS232 then it's the paper/printer equivalent of a glass terminal. You could download text files to the terminal using TeraTerm or Kermit.
 
That is amazing! I just ordered a nixie tube clock kit from pv electronics that I have been saving for for a really long time but this is next on my wishlist!
Wow, those things are getting expensive; I sure regret throwing out a case of 24 pcs. 6" tall Burroughs Nixies...

Re the Teletype: don't forget the mechanical challenges. They take a fair bit of maintenance and some special tools; lots of little levers and springs in there, sticky oil and grease, dirty contacts, none of it easy to get at...
 
I think I might be ok with the machine being gummed up All of my selectrics were and I was able to get those working good with allot of digging for Manuel's
About the Nixie tubes I think allot of sellers are just milking the price I got 6 in-14 tubes for 40.00 from ukrane and I think I payed too much but these were expensive when new.
 
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