On 9/9/2013 12:59 AM, Quasar Chunawala wrote:
Today, the mainframe staff in any enterprise work on PC running special software(the terminal emulator) to connect to the *mainframe server* over the company intranet. But, back in the 1960's, when mainframes were young, what were some of input devices? Has anyone typed TSO or compiled programs on a tele-typewriter model 33? What was it like to work on a key-punch machine? How was the experience? I suppose, 3278 terminals were introduced much later by IBM.
In the early days, everything was done by punch cards. The 026 (BCD) and 029 (EBCDIC) punches were fairly easy to use, except when you got card jams due to humidity or warped cards. IBM introduced the 1050 (similar to the 1052 operators console) with an acoustic modem, and a manual, edge-fed card reader. A little later came the 2741, a modified Selectric typewriter. The 270x controllers also accepted teletypes, but IBM did not, at that time, provide TTY compatible terminals (they didn't even call them TTYs, but TWX). As you can imagine, everything was a lot slower. Almost all work was done in batch, so that you had plenty of time to desk-check (proofread) your work, whereas much work today is done by a quick change and see what happens method.
In the second half of the sixties, IBM offered the 2260 CRTs, with a maximum 12*80 screen. For business use, there was the MTST (a "secretarial" system that created text documents, with error correction, on cartridges, and a 2495 reader for the mainframe. I found it notable that you could rewrite any character on the tape, making it behave more like DASD than tape). Starting in the late sixties, terminals started to proliferate (3272, 3275, and 3276), and in the seventies almost every computer hardware company offered terminals, either TTY 33 and upward compatible, or 327x compatible (we had IBM 327x controllers, as well as ITT and AT&T ones). PRC had Sanders CRTs. All our systems staff has TI 700s at home. Did I mention that everything was slower? <g>
The installations I worked at offered Wylbur, as it was much more productive. On our 360/65, IBM had a recommendation to keep active TSO users below 10-12; by comparison, Wylbur could handle several dozens without degradation in response. Also most of the asynchronous terminals had physical tabs, making program entry much faster than writing new code on a CRT (some software supports logical tabs on these, but you can't tell what the output will look like because you could be a column over where you thought you were). My favorite terminal at the time was the Wyse-50; it not only offered a 24*80 screen, but it could be set to more lines (50*80 IIRC). And the Wyse-300 (yellow monochrome) had a raster mode, in which you could define your own characters (similar to the 3179 and 3279); I used that for a "real" cent sign and not sign in ASCII mode. A few companies provided ASCII terminals with color support, but as far as I know, these never caught on (except for games). These days we take color for granted.
Looking back on it, it was an interesting time. Everything was slower <g> Gerhard Postpischil Bradford, Vermont ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
