[GreenKeys] Teletype Model 33 ASR vs. ASR33

Sun Aug 14 11:15:41 EDT 2011

Hello,

Retro/Vintage Computing Expert Mode:: > ON <

The swapping of the type designation (KSR, ASR, RO) and model number
on teletypes is due to the computing field. On machines that spoke
ASCII the model 33 was a far, far more common terminal then it's more
robust cousin the 35. This was due to cost, for example an excerpt
from the 1970 price list for the DEC PDP-15:
(Format: <Device> <Prerequisites> <1-Shift Service Cost> <Field
Installation Cost> <Price> <Discount Status>)
> KSR 33	None	$25	$80	$1200	NO
> ASR 33	None	$30	$120	$1500	NO
> KSR 35	None	$22	$80	$3000	NO
> ASR 35	None	$25	$120	$4500	NO
Taking a look at that price list most people responsible for buying
the computer would go "So for a very small reduction in service
cost... I need to spend twice the money? Screw that we're getting a
33." So, with the fact that the most common terminal was a 33, the
model number distinction for the most part went away and what became
important - because it was *very* important to the programmer - was
whether the teletype talking to the computer was an ASR or KSR.

A KSR's input speed is limited by the speed of the typist, an ASR's
input speed is the full 10 cps (when reading tape); hooking an ASR to
a system and dumping in a tape when the system software was written
with the assumption that the TTY input is slow... will in most cases
have a software implosion (and if that doesn't happen, then the other
users who can't use the system because it's tied up listening to your
ASR will probably attempt to implode your head with office furniture).
Meanwhile, hooking a KSR up to a system that wants an ASR can result
in - again - software imploding (telling Nova RDOS to read a tape on a
KSR results in seriously screwed up software, meanwhile punching tape
on a KSR will give you some lovely pagefuls of garble).

The reason "teletype" is at the end (and not capitalized) is because
it had become a generic term to refer to a printing terminal (kind of
like how many people call tissues "Kleenex" or an x86 based computer a
PC).

Retro/Vintage Computing Expert Mode:: > OFF <

I don't quite mind which way one puts it. (I switch between the ways,
trying to remember to call it a 33KSR here, while when talking vintage
computers calling it an KSR33.) It really depends on the context.

In any case on the computing side of things the whole ASR/KSR
nomenclature disappeared upon the appearance of video terminals -- the
Teletype Model 40 does not count. (Though, with some hardware hacking
you can get yourself something that functions like an ASR teletype
with a video terminal. Still, why you would want a VT-100 ASR or
VT-220 ASR is beyond me.)

Cheers,
Christian

P.S. I like both real teletypes and their glass descendants. (The real
ones because they are - as a friend put it - "Pimptastically awesome."
The glass ones because they are conveniently simpler (I can plug a
VT-220 into my PDP-11/23 or my PC and it is useful on both).)

On 14 August 2011 10:20, tony j. podrasky <tony.podrasky at gmail.com> wrote:
> I'd like to know too.
>
> I came into the Teletype world with the words 15, 14, 28-KSR and 28-ASR.
>
> The first time I heard someone say "blah blah blah ASR28 blah blah blah",
> I figured he's probably running up-side-down shift, too...
>
> I thought maybe he should be, like, burned at the stake for that
> kind of blasphemy.
>
> Then I thought: *WWIHD?
>
> He'd probably say: "blessed are the ones on RTTY - whether they say
> 33-ASR or ASR-33, for they are all brothers under the Teletype.
>
> UE,
> W6ESE - tony
> NNNN
> CZCZ
>
> *What Would Irv Hoff Do?
>
> Wa3frp wrote:
>> Maybe someone on the list will know.  When and why did the Teletype 33 ASR
>> become an ASR33?
>>
>> I recently saw a note posted here that used the name "ASR33" and I've seen it
>> elsewhere.  Sometimes the name is completely inverted so that Teletype 33 ASR
>> is called a ASR 33 Teletype.   I've heard of mass hysteria - is this a
>> version of mass dyslexia?
>>
>> Thanks and 73 Russ WA3FRP
>>
>
> --
> Tony J. Podrasky | "I read somewhere that 77 percent of all the
>                  | mentally ill live in poverty. Actually, I'm more
>                  | intrigued by the 23 per cent who are apparently
>                  | doing quite well for themselves." -Jerry Garcia
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>