TTYs for the deaf

From: Michael Sokolov <msokolov_at_ivan.Harhan.ORG>
Date: Sat Dec 11 17:07:48 2004

Fred Cisin <> wrote:

> the ASR33 TTY is Bell 103 at 300 baud?

That's what I've always thought, anyone who knows otherwise please correct

> "MODERN" modems that will do Bell 103, will often only do it at 300 baud.

Yes, that's what I wrote in my previous post. My question about 300 baud
Teletypes went unanswered though.

I do, however, have a few TI Silent 700s. These are absolutely lovely
300 baud portable terminals, small and portable enough to compete with
modern laptops, and even though they weren't made by Teletype, I think
of them as portable teletypes. There were two versions: 703 with RS-232
interface and 707 with a built-in Bell 103 modem. My only 703 doesn't
work (the printhead moves but prints nothing), but my 707s work great,
and I do in fact travel with one to UFO conferences, etc.

I will be celebrating New Year at Butterfly Lounge (,
and I might post here from my hotel room from a TI 707 dialing into
ivan.Harhan.ORG at 300 baud! (And yes, I have the same taste in women
as in computers: I like them both BIG!)

> surely SOMEBODY knows how to write a look-up table program to translate!

Of course it's possible, it's just totally non-standard, and most importantly,
UNIX generally expects the user to have the complete ASCII set available
to him. The V7 tty driver has support for turning an uppercase-only
tty like ASR33 into a terminal with both cases in software, but emulating
full ASCII from the 5-bit TDD code seems like a bit of a stretch.

> TDDs are more expensive, and do not have a 24 x 80 screen.
> They typically have a single line display, and sometimes an
> adding machine width printer.
> For what kind of applications would you consider that interface connected
> to a timesharing system to be more usable than a personal computer,
> or a 24 x 80 screen terminal?

None. I didn't realise that TDDs were that bad, I thought that they were
more or less normal terminals, that's why I asked.

Received on Sat Dec 11 2004 - 17:07:48 GMT

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