Questions tagged [mainframe]

for questions about retrocomputing mainframes or clusters

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0answers
121 views

Hitting the CMS Limits of Portable Code

I wrote this arbitrary precision arithmetic utility on BSD in my postgraduate days, then after graduating ported it to DOS using TurboC. Was proud that it would do the same thing with 16bit word ...
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3answers
315 views

IBM Mainframe APL internals?

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
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1answer
233 views

Why did IBM develop 5250 block mode terminals when 3270 already existed?

IBM introduced the 3270 family of block mode terminals in 1971, for use with IBM mainframes (System/370 and successors). Then, in 1977, IBM introduced the 5250 family of block mode terminals for use ...
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9answers
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 ...
5
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3answers
300 views

Is this a custom NASA Langley-built computer or is this a commercial system (ca 1970's)?

CNN's NASA will name its headquarters after Mary W. Jackson, the agency's first African American female engineer and NASA news item NASA Names Headquarters After ‘Hidden Figure’ Mary W. Jackson ...
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4answers
582 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 ...
13
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2answers
2k views

What is the purpose of the yellow wired panels on the IBM 360 Model 20?

I just finished reading a story about an IBM 360 Model 20 rescue, and some of the pictures caught my eye. Specifically this one: Searching online, led me to several more pictures, all with ...
5
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2answers
413 views

Data length module of 3.2^n confusion in IBM system/360 architecture

I'm currently reading about the IBM system/360 architecture and there's a part that has me very confused: The decision on basic format (which affected character size, word size, instruction field, ...
14
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1answer
589 views

What's the deal with System/360's “USASCII” mode?

The original System/360 architecture had a bit in the Program Status Word that would select an "USASCII" mode rather than the usual EBCDIC. Setting this bit changed how the BCD arithmetic operations ...
11
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2answers
1k views

Did any 360-compatible machine implement registers in core?

In the early days of transistors, when they cost on the order of a dollar each, it was possible to implement CPU registers with magnetic cores (the technology used for main memory at the time) instead ...
17
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1answer
456 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 wasn't an universal, de-facto standard for the written representation of a hexadecimal number, different computer systems used their own ...
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1answer
88 views

Overstriking for APL on 3270s?

This question addressed the question of APL overstrikes on printing terminals. However, IBM also had 3270 video display terminals that supported APL, as well, and those, too, handled overstriking. How?...
5
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1answer
358 views

How many hours of labor did it take to assemble a minicomputer?

A minicomputer like the PDP-8 contained several thousand discrete transistors and other components, all of which had to be soldered by hand, and that was among the simplest computers on the market; ...
4
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1answer
98 views

Version list for TOPS-10?

So, does anybody have a list of TOPS-10 versions? I haven't been able to find any information aside from versions 7.03, and 7.04. are these lost to time? To clarify, I'm not asking for the software, ...
4
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1answer
194 views

Why did the CDC 6600 expand the word size to 60 bits?

According to http://www.quadibloc.com/comp/cp0201.htm The CDC 1604 used 48-bit floating point with 11 bits exponent and 36 bits mantissa. There was also a double precision format (which I believe was ...
24
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1answer
6k 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 ...
3
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1answer
131 views

What was the first company to sell an IBM compatible punchcard reader?

Punchcards were the primary way to get information into computers up through the sixties. The familiar eighty column format was designed by IBM, and was a factor in the later de facto standard eighty ...
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2answers
893 views

IBM mainframe classic executable file formats

Most modern platforms have pretty well-defined file formats; e.g. Windows uses PE, Linux and BSD - ELF (previously a.out), macOS - Mach-O, AIX - XCOFF and so on. What were (are?) common executable ...
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3answers
818 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 ...
55
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12answers
11k 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
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2answers
342 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, ...
3
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3answers
452 views

History of advanced hardware [closed]

Like most people, I grew up in the 1980s, and bore whitness to the great 8-bit home computer revolution. From where I'm sitting, "computers" started with slow 8-bit machines just powerful enough to ...
14
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3answers
665 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 ...
5
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1answer
379 views

When were floating point rounding modes first implemented?

It appears that at least some pre-IEEE 754 computers had only one hardwired floating point rounding mode, e.g. away from zero as in PDP-11 (page 154 of PDF). Which historical architectures were the ...
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0answers
171 views

Are Unisys ClearPath Libra mainframes still in use in Australia?

By use, I mean are they still actively being developed for. I know this is the case in New Zealand and USA. In particular, is ALGOL code still being written on them?
6
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1answer
245 views

Total weight of the CDC 7600?

I'm doing some research on the CDC 7600 supercomputer. I'm trying to find at least a general guess on the overall weight of the machine, preferably including the necessary cooling equipment. I know it ...
29
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5answers
5k 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 ...
28
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6answers
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 ...
7
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5answers
648 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 ...
13
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5answers
2k 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 ...
9
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2answers
291 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 ...
3
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1answer
331 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: ...
14
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3answers
684 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 ...
13
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2answers
560 views

Do any interesting POP-2 programs survive?

On a disk image (which I had for many years) from a BESM-6, I've suddenly found a working POP-2 (POPLAN) interpreter (for all these years I'd considered that area as useless bits and pieces of various ...
13
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1answer
563 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, ...