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102 votes
Accepted

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

The basic issue that paper tape is hard to edit. In theory you can cut the existing tape and splice in a new section, but in practice there is no easy way to find the correct location except by ...
alephzero's user avatar
  • 6,656
79 votes
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Why did 1950s-60s computers have such wide words?

And if you go back further, e.g. to the ENIAC, you'll see a word size of 40 bits. And if you go back even further, to mechanical calculators, you'll see word sizes determined by the number of decimal ...
dirkt's user avatar
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74 votes
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How big is a mainframe?

In the 1980's a certain bank with its headquarters in Edinburgh has a problem with (IBM) disc storage that had to be kept online for live customer account information for branch and ATM machine ...
Brian Tompsett - 汤莱恩's user avatar
57 votes
Accepted

What was the first operating system called DOS?

DOS/360 (As distinct from TOS/360, the tape OS) Announced at the end of 1964 per Wikipedia.
dave's user avatar
  • 35.9k
55 votes

What accounted for the cost of ENIAC?

R&D stuff isn't manufactured (at first). It's usually partially constructed, ripped up, and redone, multiple times, with long testing and debug cycles in between, all the while with payroll ...
hotpaw2's user avatar
  • 8,277
54 votes
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What did code on punch cards do with the other six bits per column?

TL;DR; Punch card code is not binary but a collection of n out of m encodings. Long Story Yes, really a long story, so I'll only cover the main line from Hollerith to EBCDIC. There are many sidelines ...
Raffzahn's user avatar
  • 225k
53 votes
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History behind the text column restriction

Old COBOL standards were based around 80-column punched cards, and columns beyond 71 (or 72) were reserved for line numbers. They were little used, but a numbered deck, if dropped, could be sorted by ...
Mick's user avatar
  • 2,829
45 votes
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Why was IBM's Scientific Subroutine Package superseded?

Specifically concerning EISPACK. what happened was that James Hardy "Jim" Wilkinson in the UK (whose career as an applied mathematician started with practical ballistic modelling in WWII, ...
alephzero's user avatar
  • 6,656
42 votes

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

Punch cards long long long predated paper tape. But there's a practical consideration you're not thinking of. If you had ever used punch cards and paper tape, you'd know: Punch cards can be dropped, ...
davidbak's user avatar
  • 6,334
41 votes

Can anyone help me identify this old computer part?

According to this page it's a wire punch tool for a 1940 IBM 402 computer programming board. From that page (screenshot of the page is below): 1940 IBM 402 Computer Programming Board A tidbit fact: ...
squillman's user avatar
  • 501
40 votes
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Why did mainframes have big conspicuous power-off buttons?

Yes, huge safety concerns as I remember engineers sitting inside the cabinets of large mainframes while it was running, fully powered, large currents in each cabinet powering fans. Cooling water being ...
Brian Tompsett - 汤莱恩's user avatar
37 votes
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Were any IBM mainframes ever run multiuser?

Yes. There were CP/CMS and VM/370 - true multiuser operating systems running on the mainframe with individual users logged in. AFAIK it was mainly used for software developers (to develop IBM ...
davidbak's user avatar
  • 6,334
33 votes

How big is a mainframe?

But I can't seem to find any pictures of a computer filling an entire room, much less a whole multi-story building. (Image taken form Centre for Computing History) Well, for example look at this ...
Raffzahn's user avatar
  • 225k
32 votes

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

Uppercase text only needs six bits per character. The fundamental mistake that you are making is assuming that punch codes were binary numbers. They were not. The encodings were patterns, ...
JdeBP's user avatar
  • 2,288
32 votes

Why did the VT100 terminal have to be connected to a host computer if it already had a processor?

"Having a processor" is not sufficient for something to be a general purpose computing device. The VT100 was designed for a specific purpose, and adding more features like storage and I/O ...
Greg Hewgill's user avatar
  • 7,009
31 votes

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

Although you have many correct answers describing the nature of the coding used in punched cards, no one has touched on the mechanical properties of the cards. Regular users of punched cards in the ...
Brian Tompsett - 汤莱恩's user avatar
30 votes
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What date is 74029 on an IBM Mainframe?

TL;DR: DATE=74029 reads as: Year (19)74, Day 029 (Jan 29th), It's an Ordinal Date in truncated form, expressed in terms of 2 digit year and 3 digit day of the year. Does anyone know when was it ...
Raffzahn's user avatar
  • 225k
29 votes
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What is a good COBOL specification to target when aiming to support ~75% or more of mainframe and minicomputer software bases?

[Preface: While the basic question may seem to be off-topic, as it's about today's use of COBOL, I like to see it as asking in help to educate about COBOL. The noble effort to keep the language alive ...
Raffzahn's user avatar
  • 225k
28 votes

What accounted for the cost of ENIAC?

So what was the other $478,000 spent on? Paying people to design and build it would have been a fairly big component. People often underestimate the cost of labour, particularly if it is their own ...
JeremyP's user avatar
  • 11.7k
27 votes
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References for the complexity of the COBOL language

No, COBOL is not complex and didn't require complex compilers. At least not for COBOL up to 74 (*1) which was the standard at the time of introduction of micros (mid 70s to late 80s). From the ...
Raffzahn's user avatar
  • 225k
26 votes

How big is a mainframe?

Here's a picture of the "Strela" (arrow) computer (1954) Vacuum tubes, 2000 op/sec (on 43-bit fixed point), 150kWt, 300 m³
Wheelmagister's user avatar
26 votes
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What was the most critical supporting software for COBOL on IBM mainframes?

TL;DR: Which components or facilities were the biggest obstacle to porting typical COBOL applications? Simply that there were not many applications that made sense to be ported to (desktop) micros. ...
Raffzahn's user avatar
  • 225k
26 votes
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Was any indentation-sensitive language ever used with a teletype or punch cards?

I agree to an extent that COBOL was "indentation-sensitive", but it really wasn't "indentation-sensitive" but rather "column-sensitive". The original COBOL coding format ...
mannaggia's user avatar
  • 3,264
25 votes

How big is a mainframe?

The excellent history book "AN/FSQ-7: the computer that shaped the Cold War" describes the size of a 1950's era radar monitoring air defence computer. A single installation (a single computer) was ...
David's user avatar
  • 351
25 votes
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What accounted for the cost of ENIAC?

One of the biggest factors is that when you have a machine that requires 5,000,000 successful solder joints to function properly, you need to make sure that all of your solder joints are really really ...
Oscar Smith's user avatar
24 votes

How big is a mainframe?

Here's the computer room of the Shuttle Mission Simulator (SMS), building 5 of NASA's Johnson Space Center, in the early 1980s. Most of the boxes are parts of a Sperry-Univac 1100 mainframe, but some ...
Organic Marble's user avatar
23 votes
Accepted

What was the last non-monolithic CPU to come to market?

The world of large computers is amazing. MCM systems of monstrous in the eyes of a PC user parameters were widely popular right up to the cloud revolution, and even now, taking into account legal ...
Wheelmagister's user avatar
23 votes

Was bootloading from punch cards possible on System/370 machines?

Sorry for the narrative here, but it answers the OP's question directly by personal experience. The text is too long for a comment. "Was bootloading from punch cards possible on System/370 ...
timetraveller's user avatar

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