Questions tagged [mainframe]

for questions about retrocomputing mainframes or clusters

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

I have been idly looking into how System 370 works, though mostly at software and VM/370 OS. As a part of the system generation process, one needs to use DMKDDR utility and others. So I was curious ...
Saphire's user avatar
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5 votes
0 answers
134 views

System/3: Accessing compilers from tape [closed]

I started getting into playing with the IBM System/3 emulator from simh, and found this tape - looking at the listing it looks like there's a COBOL and RPG II compiler on that tape. What would be the ...
Toasty's user avatar
  • 67
8 votes
1 answer
596 views

Were punching tools for punch cards with rectangular holes easier to keep sharp than those for round holes?

There is a question here on retrocomputing if round punch card holes where mechanically stiffer: Were round punchcard holes mechanically stiffer? I wondered if the reason for the rectangular holes on ...
Coder's user avatar
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3 votes
4 answers
459 views

Couldn't people just buy mainframes from the same manufacturer and connect them before the arpanet?

I was reading the TCP/IP Protocol Suite by Forouzan and at one point it says: In the mid-1960s, mainframe computers in research organizations were stand-alone devices. Computers from different ...
user avatar
10 votes
1 answer
1k views

Did the IBM 1401 have much better code density than the 360?

Reading an old thread https://groups.google.com/g/alt.folklore.computers/c/53C2adEQ5jE I see a surprising claim: I told an IBM salesman once that IBM had so bollixed up the architecture that our ...
rwallace's user avatar
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9 votes
9 answers
5k views

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

The VT100 terminal already had an 8080 processor. So why did it have to be connected to a host computer? Why not use its processor to perform computations? Is it because the VT100 processor's purpose ...
Noob_Guy's user avatar
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8 votes
4 answers
2k views

"Mainframe" with Z80 [closed]

Maybe a silly question but has there ever been a mainframe OS running on a Z80 system, of course with sufficient memory and memory management unit? I'm thinking of a ported MVS running, with TSO, the ...
Hennes's user avatar
  • 183
3 votes
1 answer
419 views

How does one customize the 3270 terminal login screen in VM/370?

When using a pre-built system image such as the "VM/370 sixpack" or "MVS Tur(n)key" under Hercules, when a user connects a 3270 terminal, a login screen comes up with a banned ...
rbanffy's user avatar
  • 491
10 votes
1 answer
758 views

What is the mainframe in this image in Ireland?

Someone recently posted this image of his gran (on the right). Mainframes were before my era, can anyone positively identify the model? I don't see a console in the image, which is where I would ...
Maury Markowitz's user avatar
12 votes
4 answers
2k views

History of High Availability in the mainframe and minicomputer eras?

When tracing the source of High Availability, I found to my surprise it led to a company named Tandem Computers which since 1974 made a series of minicomputers called NonStop system, to my surprise ...
Schezuk's user avatar
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7 votes
1 answer
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Mainframe Hater's Handbook?

The famous The UNIX-HATERS Handbook claims this mailing list had been inspired by TWENEX-HATERS(1) and other *-LOVERS mailing lists, a long tradition of MIT. Moreover, the quote below implies there ...
Schezuk's user avatar
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2 votes
2 answers
250 views

How the I/O performance of legacy mainframes/minicomputers in different architectures is measured and benchmarked comparatively?

Powerful in computing power, mainframes were irreplaceable thanks to the capability of processing numerous transactions rather than doing the math. While computing power is measured in FLOPS and MIPS, ...
Schezuk's user avatar
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7 votes
1 answer
294 views

How did Bell Labs start to work on Project MAC?

Did Bell Labs approach MIT or was it the other way around? Did participating in Project MAC come from researchers requesting management at Bell Labs/MIT or did management make the decision due to ...
Knickers Brown's user avatar
21 votes
7 answers
4k views

References for the complexity of the COBOL language

One thing that struck me about the design of COBOL was that it was surprisingly complex, particularly for the era. As in, if I were trying to squeeze a compiler into a few tens of kilobytes of memory, ...
rwallace's user avatar
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3 votes
2 answers
305 views

How can the current date be accessed from DOS/VS assembler?

In assembler on an old /370-125 running DOS/VS I can access the TOD (Time of day) with GETIME, i.e. the time since midnight. But I want to be able to print the date.
monok's user avatar
  • 140
9 votes
2 answers
1k views

What was the second platform supported by SAP?

SAP, the well-known ERP software company, started out in the 1970s, with the first version of their software running on IBM mainframes, https://en.wikipedia.org/wiki/SAP_R/2 What was unique about R/2 ...
rwallace's user avatar
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16 votes
7 answers
3k views

Was any indentation-sensitive language ever used with a teletype or punch cards?

Most programming languages delimit block structure with punctuation e.g. { ... } or keywords e.g. begin ... end. However, some languages such as Python and Haskell delimit it with indentation (...
rwallace's user avatar
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14 votes
2 answers
498 views

Can anyone help me identify this old computer part?

I purchased two identical computer parts at an estate sale that seemed unusual. I was told that perhaps it was a component from an old IBM mainframe. I was able to date them between late 50's and ...
user avatar
10 votes
2 answers
377 views

Does anyone have any information on GUTS (Gothenburg University Timesharing System)?

Gothenburg Universities Computer Centre (in Sweden) developed a timesharing system for IBM mainframes, known as GUTS (variously expanded either as ''Gothenburg University Timesharing System'', or as ''...
Simon Kissane's user avatar
3 votes
1 answer
329 views

Mark IV - information please

I have in my library a copy of "Mark IV systems : Application Development Systems : Pocket Specifications Manual" by Informatics Inc. I can find very little about this, only a generalised ...
user avatar
21 votes
1 answer
3k views

What date is 74029 on an IBM Mainframe?

I have an old printout of a Fortran code. It's a simple code intended for educational purposes. The header is: FORTRAN IV G LEVEL 21, MAIN, DATE=74029, 15/28/03, PAGE 001 I assume it's from an IBM ...
Hanan Cohen's user avatar
8 votes
1 answer
664 views

Why did IBM skip "System/380" as a mainframe family name?

I've been reading Exhibit 14971 from US vs. IBM (Parts 1, 2, 3) which seems to give a very good overview of the history of the computer industry up to 1980, particularly the way IBM handled its ...
Wildcat Matt's user avatar
4 votes
2 answers
555 views

Why do computer rooms no longer have raised floors? [closed]

As I understand it, computer rooms in the days of mainframes and minicomputers, commonly had raised floors, so that the space under the floor could be used for power cables and cool air. I'm not clear ...
rwallace's user avatar
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8 votes
1 answer
729 views

What did the Big Red Button actually do on the IBM 4341? [duplicate]

Wiktionary explains the origin of the term molly guard: Originally a Plexiglas cover improvised for the Big Red Switch on an IBM 4341 mainframe after a programmer's toddler daughter (named Molly) ...
DrSheldon's user avatar
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14 votes
1 answer
2k views

What is a good COBOL specification to target when aiming to support ~75% or more of mainframe and minicomputer software bases?

There are many specifications for COBOL due to its long history. If one wanted to write software that would be acceptable for use in about 75% or more of existing COBOL projects on mainframes or ...
bbarker's user avatar
  • 279
5 votes
1 answer
512 views

What were the characteristics of the Siemens 8160 and 9750 terminals?

An answer to a recent question https://retrocomputing.stackexchange.com/a/22332/4274 referred to the Siemens 8160 and 9750 terminals, which struck me as interesting enough to ask about separately in ...
rwallace's user avatar
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11 votes
2 answers
1k views

Why did IBM want to keep ICL alive?

According to https://en.wikipedia.org/wiki/International_Computers_Limited International Computers Limited (ICL) was a British computer hardware, computer software and computer services company that ...
rwallace's user avatar
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5 votes
2 answers
328 views

Did any computer ever signal floating-point overflow purely with a sticky flag?

Every implementer of floating-point arithmetic, needs to think about how to signal overflow. One possible way to do it is by raising an exception, though this creates the problem that 'exception' can ...
rwallace's user avatar
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16 votes
3 answers
970 views

Why did instruction sets since the late 1970s seemingly stop including an "execute" instruction?

Many mainframe instruction set architectures (ISAs) in the 1960s included an Execute instruction, which would treat data as an instruction. I haven't found an architecture designed after 1976 which ...
Stavros Macrakis's user avatar
10 votes
1 answer
427 views

What sort of intermediate representation did the first Fortran compiler use?

Proebsting's Law asserts that improvements to compiler technology double the performance of typical programs every 18 years, but even granted that this is somewhat tongue-in-cheek, it's not really ...
rwallace's user avatar
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16 votes
0 answers
817 views

Was there a cartoon series in the UK computer press called "Computability Brown"?

My dad was a computing professional in Scotland in the 1970s. He received a couple of industry trade magazines every week, such as Computer Weekly and Computing. In one of them, I remember there being ...
scruss's user avatar
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6 votes
2 answers
1k views

Were any vacuum tube computers built with wire wrap?

I'm trying to gain some understanding of how early computers were built; as discussed in What accounted for the cost of ENIAC? the cost of first-generation computers was not necessarily mostly about ...
rwallace's user avatar
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7 votes
1 answer
422 views

Did other computer companies need to license Fortran from IBM?

Reading a fascinating online book about the history of computing, I came across this passage on http://ds-wordpress.haverford.edu/bitbybit/bit-by-bit-contents/chapter-seven/7-5-assembly-language-...
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
  • 58.4k
10 votes
2 answers
468 views

Did any core-memory computers have a read-and-erase instruction?

Magnetic core, the primary form of computer memory from the mid-fifties to the early seventies or thereabouts, had the slightly awkward property that reading it erased it, so every time the CPU ...
rwallace's user avatar
  • 58.4k
3 votes
2 answers
303 views

Could early computers use existing punch card machines?

In the early decades of the industry, computers used punch cards for data storage and transmission, partly because they were already widely used for pre-computer data processing; indeed, a major ...
rwallace's user avatar
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29 votes
2 answers
2k views

Why was IBM's Scientific Subroutine Package superseded?

It is a familiar fact that scientific software tends to do a lot of vector arithmetic and similar, that one does not want to keep rewriting the low-level code for such, so the usual practice is to use ...
rwallace's user avatar
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37 votes
13 answers
8k 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
  • 58.4k
9 votes
1 answer
969 views

How many transistors in the CDC 1604?

The CDC 1604, released in 1960, was Seymour Cray's first supercomputer, and also one of the first computers made of transistors. (The IBM 7090 was released only the previous year.) How many ...
rwallace's user avatar
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8 votes
3 answers
644 views

Uh, oh, I've woken up in 1973. Can I get a job in computing? [closed]

I've woken up in 1973. Until I can figure out how to monetize my knowledge of coming political, economic, and social trends, I need to support myself somehow. So... I walk into one of the major ...
SlowMagic's user avatar
  • 205
4 votes
2 answers
332 views

Did communication between a PLATO terminal and mainframe use pushes?

I'm trying to learn more about how the PLATO system worked with respect to communications. I've read some of the specs, but coming from a web-background I'm unfamiliar with the underlying way that the ...
Luke's user avatar
  • 141
9 votes
6 answers
699 views

Besides the IBM 709 and its descendents, did any other machine have "slightly longer" registers?

This question occurred to me while I was formulating this answer about arithmetic versus logical shifts. The IBM 709, and its descendant the 7090, etc., is a 36-bit mainframe with a classical single-...
another-dave's user avatar
  • 33.5k
25 votes
7 answers
6k views

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

This answer to the question "What was the rationale behind 36 bit computer architectures?" makes the point that early computers were assembled by hand, rather than having central processing ...
DrSheldon's user avatar
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10 votes
6 answers
1k views

What did order processing on a teletype look like?

The earliest business data processing systems were based on batch processing of punchcards. Prepare cards off-line, feed a batch of them through the computer. (Why does one so often hear of payroll, ...
rwallace's user avatar
  • 58.4k
17 votes
1 answer
1k views

How did SABRE work interactively without screens?

The SABRE airline reservation system went online in 1964, astonishing the world by being among other things the first large-scale interactive computing system. Once the IBM 3270 video terminals were ...
rwallace's user avatar
  • 58.4k
6 votes
1 answer
309 views

What information was present in line printer printout cover/trailer?

Nowadays, in corporate offices where there are typically several office printers per floor, sending a file to a printer does not result in any additional pages identifying the print job, at least by ...
Leo B.'s user avatar
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6 votes
2 answers
282 views

Documents about timesharing systems, access and resource control and its financials

I delved a bit into the origins of (commercial) timesharing and it seems there have been very interesting computing hardware and software (architectures) which have become relatively unknown but may ...
2080's user avatar
  • 161
4 votes
1 answer
225 views

Has a retargetable disassembler been used successfully for a word-oriented mainframe architecture?

Among many modern disassembly/reverse engineering tools, has any been used to disassemble legacy code for a word-oriented mainframe, preferably with a non-power-of-2 word length, like CDC 6600 (60 bit)...
Leo B.'s user avatar
  • 18.3k
1 vote
0 answers
138 views

Record definitions with IBM COBOL and IMS

A common technology stack for line of business applications in the sixties and seventies was IBM COBOL with the IMS database. I'm curious about how the combination handled record definitions. COBOL ...
rwallace's user avatar
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21 votes
17 answers
5k views

Were any IBM mainframes ever run multiuser?

Now of course there is a sense in which they were – some mainframe installations supported thousands of users! But there is a distinction. Consider the familiar fixture in so many 80s computer science ...
rwallace's user avatar
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