Check out Harold "Bud" Lawson's article, "The March into the Black Hole
of Complexity" in the May 2018 issue of Communications of the ACM.
Bob
On 2018-06-18 11:01 AM, Ian Clark wrote:
Hats Off to you, Joey, for some serious gap-filling. What's "Chat" for, if
it isn't for war stories?
This post will be one of my major references for my multi-volume
work-in-progress: "The Paucity Of Evidence For Intelligent Design In The
Evolution Of Computers."
On Mon, Jun 18, 2018 at 4:43 AM, Joey K Tuttle <[email protected]> wrote:
I have followed this galloping thread and finally nostalgia is causing me
to add to the detritus.
For the last 50+ entries in the thread, I've been wondering -
Did this [d]evolving discussion answer the original questions, asked a
month ago, by "Jane the novice of J" <[email protected]> ?
Or, did it cause Jane to run away from the forum laughing or ???
Jane (if you are still around), what say you?
Clearly Jane's questions piqued a lot of comments.
The APL character set has been an interest of mine for quite a long time.
I, like many others, learned APL without having access to the APL
characters (using an IBM1050 connected by phone, at 134.5 baud, to the
"original" APL machine at IBM Yorktown Heights Research Labs - I was
working for IBM in Boulder CO c. 1969)
About the Selectric Type element - it came in two variations,
Correspondence (IBM P/N 1167987) and BCD (P/N 1167988). The order of
characters was different - the BCD variation was the only one supported on
the 1050. The much classier 2741 was aimed at office workers rather than
computer programmer/operators and introduced the Correspondence code set.
If you were ordering a 2741 and specified the type element to be one of the
APL ones, that determined the code set used to communicate with the
mainframe. When using a 2741, APL (thanks to RDMoore) noted the first typed
character in a login e.g. the ) in )2001:woohoo and selected the
appropriate character table to deal with BCD versus Correspondence coding.
If the first line was just the character ) then a line of overstrikes
was made to obscure the login credentials. Lots of people rolled the paper
up so they could reveal their login if they needed to check for typing
errors.
An amusing side effect was that TSO (Time Sharing Option of the IBM 360
OS, where hundreds of key pounding programers were engaged in the
development of FS mentioned in an earlier message) would only support BCD
coded communications. So, if someone ordered a 2741 with APL element 987,
then TSO users were excluded from using that device ... Well, actually, the
programmers usually called for a service guy to convert the 2741 to BCD
which required mechanical replacement of the bars connecting the keyboard
to the internal mechanisms (an hour or 2 of tedious work) to allow the
terminal to work with TSO...
Here is a picture of an APL (BCD) Selectric type element -
http://bpi.1e6.com/APL988.jpg
The discussion of printing APL at high speed also evoked lots of memories.
My first job at IBM was testing the 1403N1 printer and the UCS feature
(this was before APL existed...) A side note is that the UCS feature, which
allowed the novel ability to print upper and lower case letters, was
developed in part because a famous televangelist wanted to buy one to send
large numbers of personalized letters to his flock. The individually
replaceable type elements on the 1403 train (versus the chain, actually a
belt with type elements affixed to it, of earlier models) made APL support
possible. Here is a picture of some 1403 type slugs (as they were called)
with APL characters on them - http://bpi.1e6.com/1403_UCS_APL.jpg
You can see that the slugs travelled on a monorail and were gear driven
(pushed) around an oblong track. There were 132 hammers (in a 13.2 inch
span), on the other side of the 14 inch wide inked ribbon and fanfold
paper. Those hammers being triggered, at the appropriate instant, to slam
the paper against the ribbon and type slug. It was a very noisy operation,
the model N1 had much larger covers designed to reduce the noise. Some
clever people learned to play tunes on the 1403 by carefully arranging the
text being printed... You can read more about various models of the 1403
at https://en.wikipedia.org/wiki/IBM_1403
Researching this stuff turned up some interesting pages that dive into
things about APL and its characters and keyboards -
http://www.rexswain.com/aplinfo.html
Here is some information about the 2741 in general (including mention of
APL) -
https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72ved
xjQkDDP1mXWo6uco/wiki/IBM_2741.html
Ahh, the "good old days" ..
On 2018Jun 17, at 11:07, Don Guinn <[email protected]> wrote:
When STSC came out with an APL for the PC I got quite good at reading the
extended ASCII characters as their APL equivalent. It was really great
when
I finally broke down and bought the APL character generator chip from
STSC.
On Sun, Jun 17, 2018 at 10:26 AM Devon McCormick <[email protected]>
wrote:
The APL print train we had on our IBM line-printers was adapted from a
"library" chain because it had Greek letters on it. If you ever looked
at
the chain after it had been in use for a while, you would see one shiny,
unused character on it: the lower-case lambda which was a remnant of the
original chain but was not used in APL.
On Sun, Jun 17, 2018 at 10:15 AM, Robert Bernecky <
[email protected]>
wrote:
A few points:
- The BGT (Blasted Goldball Terminals) were indeed noisy, but
they did make a better carbon copy than the 327X screens.
- I wrote what was the first "teletype support" for SHARP APL,
I think in 1972 or 1973, for our University of Toronto in-house site.
Character mapping, was a nightmare, and none of us (Roger Moore
and I) were never happy with any of the schemes we used for them.
- The APL-ASCII terminals came along later, in two flavors -
"bit-paired"
and "typewriter-paired", due to the terminal manufacturers' inability
to agree on anything. These were either dot-matrix terminals
or "print wheel"-based ones. I think the latter were made possible by
the advent of small, inexpensive stepping motors.
- We did have APL print trains on the 1403N1 printers with UCS.
The earlier 1403 printers, with print chains, did not have APL,
so this was A Great Advance. The print chains were not amenable
to local mods, but the trains had print slugs that you could replace,
to make a custom character set.
Bob
On 2018-06-17 04:18 AM, Ian Clark wrote:
At the IBM Scientific Centre in Peterlee we had 3270-series terminals
for
APL characters from 1975, I'm pretty sure. But I learned my APL around
1973
on an EBCDIC-only 3277. No, I didn't use that absurd curly bracketed
notation – the first mainframe APL I used was APLSV, which had
separate
256-byte input- and output-tables as editable text files. If you had a
spare afternoon you could customise them however you liked, and I
cobbled-up a usable APL alphabet (small-e for epsilon, small-i for
iota,
etc) omitting the rarer characters like domino and covering them if
needed,
or copy/pasting the character from quadAV.
When at last I was able to type real APL characters I didn't take to
them
at all – I couldn't read the code.
But nobody ever read the code. APL was proud of being a Write-Only
language. But I felt the shame. There I was, able to read assembly
code
as
fluently as a newspaper, but I couldn't read an APL program I had just
written.
Fortunately I never had to use one of those blasted golfball terminals
which sounded like a tommy gun. They were in heavy use by our project
partners ADSS Mohansic for prototyping software (in APL) intended for
the
hush-hush FS (Future-Series) mainframe. When you walked into their
lab,
with a hundred APL programmers all beavering away, the noise was
deafening.
In those days computers were IPL-ed daily (Initial Program Load-ed) –
and
the FS prototype took longer and longer to IPL as emulation piled on
emulation (I think they were using APL to emulate the instruction
set!)
Eventually it exceeded 24 hours, at which point the project was
cancelled,
to great staff and customer consternation.
So the story goes.
Shortly afterward, on one of my regular transatlantic jaunts, I
referred
airily in conversation to an "Iverson Ball". My interlocutor, a
born-again
evangelical, curtly informed me it was called the Iverson Printing
Element.
Ian
On Sat, Jun 16, 2018 at 10:26 PM, Don Guinn <[email protected]>
wrote:
Other problems. Never heard of a print train with APL characters for
high
speed printers. Had to have a special type ball for Selectric
typewriters.
It wasn't until the late 1970's that teletype matrix terminals
started
supporting APL characters. Likewise for 3270 monitors.
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Robert Bernecky
Snake Island Research Inc
18 Fifth Street
Ward's Island
Toronto, Ontario M5J 2B9
[email protected]
tel: +1 416 203 0854
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Devon McCormick, CFA
Quantitative Consultant
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Robert Bernecky
Snake Island Research Inc
18 Fifth Street
Ward's Island
Toronto, Ontario M5J 2B9
[email protected]
tel: +1 416 203 0854
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