My First « Near Working » Teletype ASR-33

[KraftwerkNation63]

Hi Everyone,

I see that I have put my topic in the wrong section. I’m not German, so I post this topic in the international section. Maybe someone of you, remember my first presentation, of my Sagem SP5A. Unfortunatly, the documentations, spare parts, etc... Are very difficult to found. And the "specific", two voltage system, of the Sagem is a brake to the idea to repare it. So, i have take the decision to sell it!

I have found, on the road of my holiday, a ASR-33. In working condition when he was stored. 15 years ago...! After a first start, the situation, is i think not bad. Don't hesitate to say advice to me. Because, i am a really beginner.

Here the movie of the first start:



So, the next step, is to try to limit the problem of the "double character" or "wrong character", after that, try to found the missing parts, and try to connect it to your network with your help.

Thanks for your help.

Théo

[M1ECY]

Hello Theo,

Okay, so the ASR33 you have there is a 7bit machine, so for computer use, rather than Telex (Telex machines are 5 bit - like your Sagem SP5)

This is why the paper strip you had at 17mm wide is too narrow for this machine.

This also explains the "Shift" Keys and CTRL Keys - these are part of the ASCII character set, not part of the ITA2 character set as used in Telex systems.

The double printing of characters is almost certainly down to the machine requiring a good clean and full lubrication service.

Hope this helps
Sean

[KraftwerkNation63]

Hi Sean,

Thanks for your answer. Can I use this as a Teletype? Or it is impossible?

Of course, I will read the cleaning part for the keyboard. Maybe after a cleaning all will be nice.

Theo

[M1ECY]

Hi Theo,

So the machine is a Teletype (Registered Trade Mark)

For Telex (and I-Telex) the standard is 5 Bit using ITA 2 character set, and 50 Baud.

Fred may have designed some clever software that might allow 7 Bit ASCII machines to exist with I-Telex, but I do not know.

As the machine stands, it is a terminal unit for a computer system. Some other people might offer more information, but generally I would say that this machine will be harder to get working with I-Telex than your Sagem would have been.

It is not just the keyboard that needs cleaning, it is all the code bars, pivots, clutches, and other mechanical parts inside the machine - basically a full service.

The standard advice here is to obtain some spray oil (Not WD40) and literally spray all the metallic parts, then leave the machine for a week or two to allow the oil to soften any sticky residue, then gentle cleaning with cloths, brushes and some kind of gentle spirit (not acetone or paint thinners) - then follow the relubrication procedure as set out in the ASR-33 manual - there will probably be around 100 lubrication points that will require a light machine oil (32 grade hydraulic oil works well).

There may be members here that understand the machine better than I do, but it is much more complicated than a fully mechanical machine.

I wish you luck

Cheers
Sean

[FredSonnenrein]

Fred may have designed some clever software that might allow 7 Bit ASCII machines to exist with I-Telex, but I do not know.

Yes, there is a version of the interface boards to "talk" with 110 baud and 7 bit and ASCII coding.

This version can be adapted to other speeds.

Best regards,

Fred

[KraftwerkNation63]

Hi Sean,

Thanks for your answer. Unfortunatly, no choice is good because in this situation. First, for a totally mechanical machine, in France, nobody is able to reapare this. So the only solution is to found a mechanical machine in fully working condition, so near impossible. Or buy it to an passionate person. Second, for a semi-mechanical machine as this ASR-33, the parts are more easy to found, but the problem is that the system is of course "more complex"...

Here in France, i don't know in other country but this type of machine are really scarce. For the Sagem, i know that is a pity but nobody was in condition to help me "physically". And nobody in France is interested by this machine... So hard to found a solution. And the system to perforate the paper tape was missing.

So, in this condition, i have a very important question to ask. If i understand good, Fred have "create" a system to imitate the Telex Network? And i must by an system to him to connect my Teletype? For the moment, the ASR-33 is too modern for my taste but it is the first "near working" machine that i have found on the french market. In this condition, is it possible for exemple to making working the ASR-33, and when i found a nice Teleprinter, at my taste, use the system on the other Teleprinter?

I remind you an other thing. I have a very low skill in computer science and electric. I have more skill in mechanic. Do you think it is an "possible project" for a person like me to make working a teletype?

Thanks for your help.

[M1ECY]

Hi Theo,

Yes, Fred has made some special software to allow the ASR-33 to work with I-Telex, I am no expert with this, but I think it works by receiving the ASCII text at 110bd and buffering onto I-Telex at the normal 50bd - The ASCII alphabet is then converted to ITA-2, which does mean you loose some of the characters, and the shift keys are not needed either.

I-Telex is very flexible - you can add interface cards to suit most machines.

Everyone can have a working teletype, it just takes perseverance, and willingness to try new things and maybe a little self teaching too.

Cheers
Sean

[FredSonnenrein]

Yes, Fred has made some special software to allow the ASR-33 to work with I-Telex, I am no expert with this, but I think it works by receiving the ASCII text at 110bd and buffering onto I-Telex at the normal 50bd - The ASCII alphabet is then converted to ITA-2, which does mean you loose some of the characters, and the shift keys are not needed either.

I-Telex is very flexible - you can add interface cards to suit most machines.

That's all correct...

[KraftwerkNation63]

Thanks for your answer. So what will be the next step to go in direction of make my ASR-33 working in the I-Telex system?

(After my keyboard cleaning of course).

Best regards

Theo

[M1ECY]

Hi Theo,

So, first make the machine work reliably in local mode, this means getting the machine to print characters correctly and without repeats.

Then we need to understand how it is configured for "Line" current, and find some sensible and simple way to create a safe line current to test that the machine behaves correctly.

Do you have I-Telex as a system already? otherwise we need to think about some way of testing the machine in "Online" mode