Happy Mainframe Day
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Happy Mainframe Day!
OTD 1964: IBM announces the System/360 family. 8-bit bytes ftw!Shown: Operator at console of Princeton's IBM/360 Model 91.
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Happy Mainframe Day!
OTD 1964: IBM announces the System/360 family. 8-bit bytes ftw!Shown: Operator at console of Princeton's IBM/360 Model 91.
@aka_pugs I wonder if we're going to see this kind of nostalgia in another 40-50 years but for the initial rollout of quantum computing hardware
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Happy Mainframe Day!
OTD 1964: IBM announces the System/360 family. 8-bit bytes ftw!Shown: Operator at console of Princeton's IBM/360 Model 91.
@aka_pugs The high school I went to had several terminals connected to an IBM 360 at the University of Minnesota. I started to learn how to code using those terminals. This was in the late '60s.
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@aka_pugs The high school I went to had several terminals connected to an IBM 360 at the University of Minnesota. I started to learn how to code using those terminals. This was in the late '60s.
@mappingsupport @aka_pugs What sort of terminals? Teletypes? And they had leased lines to the university?
360/91 was the high end mainframe at the time, that thing could have megabytes of RAM made by people manually stringing cores on wires.
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Happy Mainframe Day!
OTD 1964: IBM announces the System/360 family. 8-bit bytes ftw!Shown: Operator at console of Princeton's IBM/360 Model 91.
So Awesome!!! I got to play on a 370 when I was an undergrad, it was pretty awesome for the time. Rexx was my first exposure to scripting languages, it was clunky but really cool. You could emulate a terminal in it by stacking commands into storage in reverse order and then playing 'em back IIRC.
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@mappingsupport @aka_pugs What sort of terminals? Teletypes? And they had leased lines to the university?
360/91 was the high end mainframe at the time, that thing could have megabytes of RAM made by people manually stringing cores on wires.
@mike805 @mappingsupport Princeton's 360 was purely batch - no terminals other than the operator console (IBM 3215?). But there was a 370 in the same room running time-sharing. IBM's native terminals were the 3277 (weird-ass CRT) and the 2741 (printer/keyboard based on the Selectric typewriter). But as time went on, ASCII CRTs were dominant.
And the model 91 had a whopping 2 (two!) megabytes of core.
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@mike805 @mappingsupport Princeton's 360 was purely batch - no terminals other than the operator console (IBM 3215?). But there was a 370 in the same room running time-sharing. IBM's native terminals were the 3277 (weird-ass CRT) and the 2741 (printer/keyboard based on the Selectric typewriter). But as time went on, ASCII CRTs were dominant.
And the model 91 had a whopping 2 (two!) megabytes of core.
@aka_pugs @mappingsupport So you could use ASCII character terminals with a mainframe?
I know the 3270s were more like a browser where you got a whole screenful at a time, and the response was only sent back when you pressed enter or a function key.
I ran into one of those IBM block terminals at a university library once, and it's still one of the fastest interactive query systems I've ever seen. They had that optimized.
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@mappingsupport @aka_pugs What sort of terminals? Teletypes? And they had leased lines to the university?
360/91 was the high end mainframe at the time, that thing could have megabytes of RAM made by people manually stringing cores on wires.
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Happy Mainframe Day!
OTD 1964: IBM announces the System/360 family. 8-bit bytes ftw!Shown: Operator at console of Princeton's IBM/360 Model 91.
@aka_pugs Really was the beginning of the modern era of computing, starting with the normalisation of 8-bit bytes and character addressable architecture.
Well, that's all true so long as we don't mention EBCDIC
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@aka_pugs Really was the beginning of the modern era of computing, starting with the normalisation of 8-bit bytes and character addressable architecture.
Well, that's all true so long as we don't mention EBCDIC
@markd They had ASCII mode, but the peripherals never got the memo.
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Happy Mainframe Day!
OTD 1964: IBM announces the System/360 family. 8-bit bytes ftw!Shown: Operator at console of Princeton's IBM/360 Model 91.
@aka_pugs Only 8 bits per word? That will never be enough for anyone! 18 bit words like the PDP-1 or 12 bit words like the PDP-8, now that's serious computing! Also, 8 bit words make octal representation quite pointless…
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@markd They had ASCII mode, but the peripherals never got the memo.
@aka_pugs @markd ASCII mode was only about how some of the decimal arithmetic instructions behaved. For the printers, the character set was pretty arbitrary, and the Translate instruction would have allowed for easy compatibility no matter what. The real EBCDIC issue was the card reader—and per Fred Brooks, IBM wanted to go with ASCII but their big data processing customers talked them out of it.. But that's a story for another post. (And 8-bit bytes? Brooks felt that 8-bit bytes and 32-bit words was one of the most important innovations in the S/360 line. It wasn't a foregone conclusion—many scientific computing folks really wanted to stick with 36-bit words, for extra precision. IBM ran *lots* of simulations to assure everyone that 32 bit floating point was ok.)
Why yes, in grad school I did take computer architecture from Brooks…
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R relay@relay.infosec.exchange shared this topic
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@aka_pugs Really was the beginning of the modern era of computing, starting with the normalisation of 8-bit bytes and character addressable architecture.
Well, that's all true so long as we don't mention EBCDIC
@markd a former colleague of mine used to joke that EBCDIC was the first strong crypto algorithm to be exported from the US
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@aka_pugs Really was the beginning of the modern era of computing, starting with the normalisation of 8-bit bytes and character addressable architecture.
Well, that's all true so long as we don't mention EBCDIC
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@aka_pugs @markd ASCII mode was only about how some of the decimal arithmetic instructions behaved. For the printers, the character set was pretty arbitrary, and the Translate instruction would have allowed for easy compatibility no matter what. The real EBCDIC issue was the card reader—and per Fred Brooks, IBM wanted to go with ASCII but their big data processing customers talked them out of it.. But that's a story for another post. (And 8-bit bytes? Brooks felt that 8-bit bytes and 32-bit words was one of the most important innovations in the S/360 line. It wasn't a foregone conclusion—many scientific computing folks really wanted to stick with 36-bit words, for extra precision. IBM ran *lots* of simulations to assure everyone that 32 bit floating point was ok.)
Why yes, in grad school I did take computer architecture from Brooks…
@SteveBellovin @aka_pugs If you were on the non-EBCDIC side of the fence you got the impression that IBM sales pushed EBCDIC pretty hard as a competitive advantage - even if their engineering covertly preferred ASCII.
The 32-bit word must have been a harder-sell for the blue suits since the competition were selling 60bit and 36bit amongst other oddballs.
Fortunately the emergence of commercial customers marked the declining relevance of scientific computing... Did IBM get lucky or were they prescient?
But yeah, the S/360 definitely marked the end of the beginning of computing in multiple ways.
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@SteveBellovin @aka_pugs If you were on the non-EBCDIC side of the fence you got the impression that IBM sales pushed EBCDIC pretty hard as a competitive advantage - even if their engineering covertly preferred ASCII.
The 32-bit word must have been a harder-sell for the blue suits since the competition were selling 60bit and 36bit amongst other oddballs.
Fortunately the emergence of commercial customers marked the declining relevance of scientific computing... Did IBM get lucky or were they prescient?
But yeah, the S/360 definitely marked the end of the beginning of computing in multiple ways.
@markd @SteveBellovin IBM had a huge lead in commercial data processing because of their punch card business. And that world did not care about floating point. The model 91 was an ego-relief product, not a real business. IMO.
Data processing and HPC markets never converged - until maybe AI.
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@markd @SteveBellovin IBM had a huge lead in commercial data processing because of their punch card business. And that world did not care about floating point. The model 91 was an ego-relief product, not a real business. IMO.
Data processing and HPC markets never converged - until maybe AI.
@aka_pugs @markd @SteveBellovin
But still, FORTRAN IV got lots of use especially on 360/50…85 in universities & R&D labs. i suspect not much on /30 /40.
I still think of 360 as a huge bet to consolidate the chaos of the 701…7094 36-bit path and the 702…7074 &1401 variable-string paths.
And for fun: I asked both Gene Amdahl & Fred Brooks why they used 24-bit addressing, ignoring high 8-bits… which caused a lot of problems/complexity later.
A: save hardware on 360/30, w/8-bit data paths. -
@aka_pugs @markd @SteveBellovin
But still, FORTRAN IV got lots of use especially on 360/50…85 in universities & R&D labs. i suspect not much on /30 /40.
I still think of 360 as a huge bet to consolidate the chaos of the 701…7094 36-bit path and the 702…7074 &1401 variable-string paths.
And for fun: I asked both Gene Amdahl & Fred Brooks why they used 24-bit addressing, ignoring high 8-bits… which caused a lot of problems/complexity later.
A: save hardware on 360/30, w/8-bit data paths.@JohnMashey @markd @SteveBellovin I love this quote from Boeing about the 360.
See https://drive.google.com/file/d/1Zb6s_Ti7ON-6DNGg8VB2VvLSbh72_bgM/view?usp=sharing
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@JohnMashey @markd @SteveBellovin I love this quote from Boeing about the 360.
See https://drive.google.com/file/d/1Zb6s_Ti7ON-6DNGg8VB2VvLSbh72_bgM/view?usp=sharing@aka_pugs @JohnMashey @markd @SteveBellovin Huh, interesting comment on hex floating point. I’ve long thought that a controversial choice. I remember hearing an IBM numerical analyst claim that the hex floating point was “cleaner” than competing formats (this predated IEEE 754) but much literature today echoes the criticism given here that the hex format effectively shortens the significand.
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@aka_pugs @markd @SteveBellovin
But still, FORTRAN IV got lots of use especially on 360/50…85 in universities & R&D labs. i suspect not much on /30 /40.
I still think of 360 as a huge bet to consolidate the chaos of the 701…7094 36-bit path and the 702…7074 &1401 variable-string paths.
And for fun: I asked both Gene Amdahl & Fred Brooks why they used 24-bit addressing, ignoring high 8-bits… which caused a lot of problems/complexity later.
A: save hardware on 360/30, w/8-bit data paths.@JohnMashey @aka_pugs @markd @SteveBellovin sounds like Motorola copied their reasoning years later, with the MC68000.
For us UMich folks, the 360/67 was the machine that mattered...
