On Mar 8, 12:04=A0am, "Adam H. Kerman" <a...@[EMAIL PROTECTED]
> wrote:
> There were developments beginning in the mid 1950's. The standards
> committee was formed in 1960. The big deal was convincing AT&T to
> join, and thus did not promulgate a 6-bit code, and then promoting
> its use internationally.
Where did you read this?
> What I read is that the pizza and beer didn't run out for two years
> because all the major cor****ations took parochial attitudes, but
> finally, IBM and Teletype agreed on something resembling IBM's original
> proposal, which broke the logjam.
I don't understand what you mean: What is the "pizza and beer"
reference? What exactly did IBM and Teletype agree on and what was
the logjam? Was this before or after System/360?
I strongly doubt IBM would've considered a code that wasn't related to
its punch cards since in 1962 punch cards remained a very big part of
I/O for computers.
Remember that IBM had converters to translate Baudot into Hollerith
(punched card) since 1940. Companies used this to transmit data.
> >There's a =A0Western Union Technical Bulletin available on the web with
a=
n
> >article about it if anyone is interested. =A0As an aside, WU wasn't
thril=
led
> >about it, it was quite happy with its 5-bit Baudot*.
>
> Heh. Lack of lower case letters and punctuation and control characters
> didn't make users all that thrilled with it, I suppose. The original
> ASCII, as a political compromise, was designed for expansion and left
> room for more control characters and lower case but didn't start with
> them.
For data transmission requirements of the early 1960s, there was
little desire for lower case. Indeed, many people wanted a shorter
code since each bit was expensive in those days. IBM computers were 6
bit and there was internal resistance to go to 8 bit since it used up
more core and drove up the cost.
> >About that time Teletype Corp came out with the model 33 ASR which
> >used it. =A0But I think most business communications, via WU Telex or
> >AT&T TWX stayed with Baudot until the end.
>
> From what I read, Teletype implemented ASCII immediately, so I don't
think=
> that's correct.
Teletype offered new machines in ASCII, but it also offered new
machines in Baudot as well. The business telegraph switched networks--
Telex and TWX--mostly stayed with Baudot (I used them well into the
1970s). The older models remained in service. I'm not even sure
when the networks would even accept ASCII. It was of no value if you
were sending ASCII to a Baudot machine. Also, for telegraph
transmissions ASCII didn't give you anything.
The ASCII machines tended to be used as computer terminals, not
telegraph terminals.
> In a paper tape punch machine, BS would position the punch over the most
> recently punched character. It would then be followed by DEL (which
> punches all holes! 1111111) to obliterate the mistrake. So mistakes were
> corrected by a two-code sequence in a paper tape medium.
I don't believe tape punches had an _electric_ backspace feature. If
one was preparing a tape, one would hit a _manual_ backspace button,
then hit RUBOUT which was all holes. That was typical practice; to
fix it offline before sending.
For computer terminals, there was a backward arrow character (I don't
know what it is today). That merely told the computer to disregard
the prior character. Strictly software interpretation.
> >I miss the functionality of cntl-G, the bell. =A0On my PC, if I write a
> >simple program to issue that, it will beep, but nowhere else.
>
> Hm. You want a bell on your laser printer?
Sure, why not? My dot matrix printer sup****ts it (makes a beep).
Good way to send a signal to the operator.
> He also explains another control character I've always been curious
> about, VT veritical tab. This was used by a business to fill in a form
> remotely. Data was sent, with a VT to move the paper to the next
vertical
> tab. How was this controlled? With a special paper tape loop called a
> Vertical Forms Unit! One would punch holes corresponding to the next
> position you need the paper to be in to fill in the next field on the
form=
..
Those Teletypes required a sprocket feed.
IBM tab machines had this carriage control for many years. You had a
choice of codes. This was carried over to programming where you could
say to go to a particular channel code and the paper would advance.
Now it's all electronic.
Interestingly, the tab machines would let you inquire about what
channel you're at on the printer control tape, while computers did not
allow that.
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