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. >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >>> >>> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > -- > Robert Bernecky > Snake Island Research Inc > 18 Fifth Street > Ward's Island > Toronto, Ontario M5J 2B9 > > [email protected] > tel: +1 416 203 0854 > text/cell: +1 416 996 4286 > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
