Questions tagged [mainframe]

for questions about retrocomputing mainframes or clusters

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5 answers
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Why did mainframes have big conspicuous power-off buttons?

Some fascinating stories in this discussion thread. It starts with discussion about computers overheating, but about halfway through the thread, it switches to discussion of mainframe installations in ...
rwallace's user avatar
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13 votes
1 answer
861 views

What is the prototype of the Eastern Bloc videoterminal Videoton 340?

Several decades ago, the Hungarian company "Videoton" manufactured a videoterminal for which I couldn't find a Western prototype. It likely existed, as the device had been assigned a "ES" number, ...
Leo B.'s user avatar
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7 votes
5 answers
968 views

When did smart terminals arrive?

In the days of mainframes and minicomputers, a common user interface was a serial terminal where each keystroke was sent to the computer, which could respond with an update to the contents of the ...
rwallace's user avatar
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37 votes
13 answers
9k views

Why were programs entered on punch cards instead of paper tapes?

Dale Fisk's Programming With Punched Cards is a fascinating account of programming in the days of punch cards. The fundamental dynamic was that early computers did not yet support timesharing. The ...
rwallace's user avatar
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34 votes
9 answers
11k views

What did code on punch cards do with the other six bits per column?

In the fifties and sixties, program source code was typically stored on punch cards, one card per line. The most common card format was the IBM 80 column by 12 row. For source code, this was commonly ...
rwallace's user avatar
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31 votes
5 answers
6k views

How was the C language ported to architectures with non-power-of-2 word sizes?

By the time the C language started to gain popularity outside of the PDP-11 circles (mid-1970s), mainframes with "weird" word sizes, and no capability to address individual bytes efficiently were ...
Leo B.'s user avatar
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29 votes
6 answers
4k views

History behind the text column restriction

In the old days, I remember we were told to never go beyond the 70'th column in the text editor (the actual value was usually something above 70, but less than 80). Further, at least in the program I ...
Burhan Khalid's user avatar
26 votes
7 answers
5k views

What was the most critical supporting software for COBOL on IBM mainframes?

Over the past half-century, one of the largest trends in the computer industry has been the replacement of mainframes by microcomputers. Not total by any means – there are still many mainframes in ...
rwallace's user avatar
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24 votes
4 answers
5k views

What accounted for the cost of ENIAC?

I'm used to the fact that first-generation computers were very expensive, which I had always assumed was because they contained large numbers of vacuum tubes, each of which is a rather complex, high ...
rwallace's user avatar
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23 votes
1 answer
894 views

Was the IBM S/360 Responsible for Popularizating the 'A'-to-'F' Notation in Hexadecimal Numbers?

In the early history of computing before the mid-1960s, there was no universal, de-facto standard for the written representation of a hexadecimal number, different computer systems used their own ...
比尔盖子's user avatar
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18 votes
5 answers
3k views

Was there ever a genuine "mainframe-on-a-chip" microprocessor?

In the 1980s and 90s, there was a fad among the IT industry press to dub the newest "hot" microprocessor on the market as being a "mainframe-on-a-chip". I have seen this fawning description applied to ...
Brian H's user avatar
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14 votes
3 answers
1k views

Which programming systems used object files on punch cards?

In a batch programming system developed in the late 1960s - early 1970s at the Joint Institute for Nuclear Research in the city of Dubna near Moscow, it was possible to dump object files to punch ...
Leo B.'s user avatar
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13 votes
4 answers
3k views

Were round punchcard holes mechanically stiffer?

The most common punch card format was the IBM 80 column by 12 row, with narrow rectangular holes. However, there were other possibilities, such as a later IBM format that used round holes. That one ...
rwallace's user avatar
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9 votes
10 answers
3k views

How did dusty deck Fortran handle overflow?

In Fortran 77, numerical code that ran on IBM, CDC, Cray etc, how was overflow typically handled? Did it raise an exception? (I would expect such an exception to be inexact on vector machines, i.e. to ...
rwallace's user avatar
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9 votes
2 answers
416 views

Information about Sabre-ADS Model 757 terminal

Someone on reddit acquired a Sabre-ADS terminal, Model 757. They were used for airline reservation and probably connected to an IBM mainframe. Is there anything known about the pinout and workings of ...
dirkt's user avatar
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6 votes
4 answers
2k views

How was it possible to run IBM mainframe software in emulation on HP?

... At least, without getting sued into the ground? According to one of the answers to What was the most critical supporting software for COBOL on IBM mainframes? We installed a new HP replacing an ...
rwallace's user avatar
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6 votes
4 answers
1k views

Connect IBM 3481 terminal to RS232?

I recently acquired an IBM 3481 terminal. It has a parallel port, a DB-15 port (I believe for a twinax-T connector), an 8P8C keyboard connector, and a PS/2 connector. Since I don't have a vintage IBM ...
65a's user avatar
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5 votes
2 answers
668 views

COBOL and processing card files directly

COBOL was the first exercise in design of a programming language by a committee of representatives from competing companies. irrespective of one's opinion of the technical quality of the end result, ...
rwallace's user avatar
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3 votes
1 answer
590 views

Using audio tape recorders on non-personal computers?

A Soviet manual (1978) for an interactive integrated development system named ПУЛЬТ (translated as "console" or "[remote] control panel") developed for the BESM-6 mainframe contains a cryptic note: ...
Leo B.'s user avatar
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2 votes
3 answers
321 views

When/where was datum and limit relocation invented?

I recently "attended" a meeting of the UK Computer Conservation Society on the subject of LEO (Lyons Electronic Office; Lyons was a bakery and cafeteria business that found itself designing ...
dave's user avatar
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