Questions tagged [mainframe]

for questions about retrocomputing mainframes or clusters

Filter by
Sorted by
Tagged with
5 votes
1 answer
779 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: ...
12 votes
4 answers
638 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 ''...
17 votes
2 answers
4k views

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 ...
8 votes
1 answer
809 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) ...
5 votes
0 answers
137 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 ...
3 votes
4 answers
475 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 ...
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 ...
8 votes
1 answer
630 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 ...
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 ...
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 ...
19 votes
4 answers
1k views

Is there a line printer sound simulator?

To improve "authenticity" of a mainframe simulator and for an additional nostalgic effect, I'd like to add sounds of a line printer to it. They should be similar enough to the original sounds for ...
16 votes
0 answers
828 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 ...
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 ...
3 votes
1 answer
451 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 ...
59 votes
13 answers
13k views

How big is a mainframe?

If you read about the history of computing, you'll hear how the first computers were "huge". You will often come across assertions that in the early days of commercial computing, a single computer ...
4 votes
2 answers
335 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 ...
10 votes
1 answer
765 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 ...
2 votes
2 answers
269 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, ...
7 votes
1 answer
300 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 ...
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 ...
7 votes
1 answer
593 views

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 ...
3 votes
2 answers
311 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.
6 votes
3 answers
622 views

Was sneakernet a job description?

'Sneakernet' is a colloquial term for moving data by walking back and forth with a removable digital medium such as a floppy disk or tape in your hand. In 'IBM's 360 and Early 370 Systems', page 533, ...
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, ...
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 ...
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 ...
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 (...
14 votes
2 answers
507 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
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 ...
23 votes
1 answer
896 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 ...
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 ...
3 votes
1 answer
354 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 ...
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 ...
27 votes
1 answer
7k views

What was the first operating system called DOS?

MS-DOS a.k.a. PC-DOS nee QDOS, was commonly just referred to as DOS. But 'disk operating system' is a very obvious acronym; there must have been previous operating systems so called. What was the ...
9 votes
6 answers
715 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-...
5 votes
1 answer
553 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 ...
9 votes
1 answer
738 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 ...
11 votes
3 answers
1k views

Patent barriers to IBM mainframe compatibility?

'Blue Magic: The People, Power and Politics Behind the IBM Personal Computer' is an excellent book, but it makes one claim I cannot quite make sense of. Page 13 of the hardback edition says: "Lowe ...
4 votes
2 answers
624 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 ...
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 ...
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 ...
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 ...
5 votes
2 answers
353 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 ...
16 votes
3 answers
990 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 ...
8 votes
4 answers
775 views

How was the APL character set represented on IBM mainframes?

The APL language used a unique set of characters, and additionally allowed overstriking of some characters on the terminal to form characters that were used in the language. When an APL workspace was ...
10 votes
1 answer
442 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 ...
5 votes
2 answers
670 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, ...
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 ...
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 ...
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 ...