New answers tagged mainframe
5
I don't know about IBM, but in the UK, people like Maurice Wilkes gained wartime practical experience with electronics operating at megahertz frequencies and with delay-line storage, this latter being used to store one radar 'frame', so that background images could be screened out by subtracting one frame from the next.
As recounted in his memoirs, this gave ...
4
There is a significant step between mechanical (digital and analogue) devices, and digital electronics: Analogue electronic equipment. It appears that this is what the assertion is referring to. The B-29 contained a lot of electronic radio equipment: https://aafradio.org/flightdeck/b29.htm. Additionally there is the https://en.wikipedia.org/wiki/H2X radar ...
0
This is a late answer but I hope that it might to some small extent be useful.
I've not delved into the original IBM APL to any extent other than to adapt my 2741 emulator to handle it, but have gone moderately deeply into other applications in particular derivatives of Ken Thompson's APL/11.
I can't remember whether the source of IBM APL was ever made ...
-2
When I worked with keypunches and card readers, the most common issue I faced was a jammed keypunch. You could often clear a keypunch with a card saw, but sometimes one of the punches stuck down, and then you needed a service call to IBM for a repair.
One of the things I most dreaded was dropping someone's card deck. It happened to all of us, and there was ...
0
One or two things not mentioned on this trip down memory lane.
Columns 73-80 were used for sequence numbers on fortran (and probably other) source code cards because the IBM card readers on the 7090 series computers did not read those columns; they read the card as 24 36 bit words.
We did use binary cards on CDC 3600 computers to store compiled programs and ...
3
More historical folklore...
As late as 1978, I worked on META-4 systems at Digital Scientific Corporation that still supported punched card readers, and even had to write microcode to allow the systems to be bootstrap loaded from a single punched card. These systems emulated IBM 1130 and 1800 computers, which were typically booted from a single punched card....
2
It's been mentioned already that cards were also used to hold binary data (and programs), specifically, using 2-columns representing 3-bytes. This must have been relatively modern, as prior to the introduction of System-360, IBM's mainframes (IBM 7090 et al) used 6-bit characters, packed 6 to a 36-bit word. I used a (then very old) IBM 7094-II back in the ...
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