Questions tagged [ibm]

For questions regarding the products of IBM, International Business Machines.

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45
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2answers
7k views

Did IBM encourage Bill Gates to retain the rights over PC-DOS?

As is well-known, Microsoft's negotiations with IBM to deliver PC-DOS 1.0 with the original IBM PC resulted in: IBM licensing the OS from Microsoft, as opposed to purchasing it outright. Microsoft ...
32
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9answers
10k 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 ...
32
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2answers
3k views

How many OS/2 viruses were there?

When I was in college, I remember IBM representatives trying to sell OS/2 Warp to students and teachers by saying that there were no (known) viruses for OS/2. (Of course, that didn't stop the makers ...
31
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2answers
4k views

Why wasn't EBCDIC designed with contiguous alphanumeric characters?

Inspired by this question on ASCII, I have wondered similar things about EBCDIC. At work we have an EBCDIC file that gets sent to a mainframe (I presume an IBM one) and to view it on my laptop I ...
27
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3answers
4k views

Why does an instruction include the address of the next instruction on the IBM 650?

The IBM 650 seems to be a load-store machine. One advantage of a load-store machine is that the instruction can be shorter because there's less pressure to pack more information into it. But the IBM ...
27
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2answers
3k views

How widely used was 0xDEADBEEF?

Inspired by some comments on the question "The history of the NULL pointer":- There was a practice in the '70s to use the hexadecimal code 0xDEADBEEF to indicate an invalid value. This could be to ...
26
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4answers
5k views

Was there a clearly identifiable "first computer" to use or demonstrate the use of virtual memory?

The NPR.org news article and podcast How The World Has Changed! Science During The 40 Years Of 'Morning Edition' includes the photo below with the caption Before the introduction of the personal ...
25
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1answer
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 ...
20
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17answers
4k 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 ...
20
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7answers
4k 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 ...
19
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4answers
2k views

Did the IBM PC use the 8088's NMI line?

As I understand it, the Intel 8088 CPU used in the original IBM PC had two interrupt lines: INTR and NMI. INTR was fed from the Intel 8259 Programmable Interrupt Controller, which handled the IRQs ...
19
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4answers
2k views

Are there statements from IBM insiders revealing why OS/2 was dropped?

In the early to mid-90s I was an OS/2 user and supporter. The operating system was originally jointly developed by both Microsoft and IBM. Both companies claimed it was the future, including public ...
19
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1answer
559 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 ...
18
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1answer
3k views

What is the function of this strange IBM apparatus?

Does anyone know what kind of device this is? I found it in my late dad's stuff, probably from the 1970s. It has no number, type, model, serial number or anything else on it that could be used for ...
18
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3answers
5k views

Is it possible to adapt a standard PC floppy drive to work in an IBM PS/2?

I have three different IBM PS/2 machines and all of them are in perfect working order—except for the floppy drives. None of the floppy drives will read disks, which means all I can do is key in BASIC ...
17
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1answer
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 ...
15
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2answers
1k 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 ...
15
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0answers
312 views

Uninstalling OS/400 by deleting one program

This is about the AS/400 which is an IBM mini-computer launched in 1988. It lives on today after several name changes and considerable hardware and software changes. It is still often informally ...
14
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1answer
2k views

Why would a CD-ROM in an MS-DOS 6.22 system not allow file access?

I have an OS/2 Warp CD that I am wanting to use as the installation media on an IBM PC 350 Pentium system. I have already installed MS-DOS 6.22 and the IBMIDECD.SYS driver for the CD-ROM drive on the ...
14
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1answer
736 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 ...
14
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1answer
279 views

Is the "IBM standard character set manual" around?

From Wikipedia's code page article: Originally, the code page numbers referred to the page numbers in the IBM standard character set manual Is any version of this publication available? I'd be ...
13
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5answers
3k views

When did IBM start to use ASCII?

I’m trying to figure out when IBM switched to ASCII and when ASCII became a worldwide standard. Moreover, did IBM make ASCII standard worldwide? What I have found: According to Wikipedia, IBM System /...
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 ...
12
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12answers
2k views

Which pointing devices were used by early laptop computers?

I've started reading this article on the history of the ThinkPad. In it, the TrackPoint (pointing stick/"nipple" mouse) is heralded as an important innovation in the design of portable computers at ...
12
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2answers
3k views

Found an IBM 5291. What is it, from when, and how much is it worth?

So, I found one of these: (It's as if it's new, it wasn't ever used, it sat on a bookshelf next to an old CRT monitor, it also has every part). On the front there's a small gray box with the text ...
12
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1answer
445 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 ...
11
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4answers
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 ...
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 ...
11
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1answer
654 views

Can the system's BIOS come from an ISA card?

If an ISA card was configured to respond to the address range of the system's BIOS (and the BIOS chips removed), could you boot from it in the same way as the system's default BIOS? Specifically, I'm ...
10
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5answers
5k views

How much data could be stored on a single punched card?

I was looking at this IBM webpage on the history of floppy disks and it says the original 8-inch floppy disk from 1971 could store 80 KB of data, equivalent to that of 3000 punched cards. So, based on ...
10
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3answers
653 views

How can I boot or extract files from an IBM PS/1 with a DoubleSpace-compressed hard drive?

I’m trying to boot an old IBM PS/1, mostly with the intention to read out its hard disk. I realized quickly that the original floppy disk drive was broken, so I replaced it with a Gotek floppy ...
10
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2answers
742 views

What year was my old, long-lost IBM PC born? And which form factor/model was it?

I've spent a ridiculous amount of time and effort over the years just trying to figure out what exact IBM product I grew up with. At last, I've finally established for 100% certain that it was a: IBM ...
10
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1answer
317 views

Why were index register contents on IBM 7090 subtracted in forming the effective address?

On IBM 709/7090/7094 mainframes, the effective address of an instruction could be modified by the contents of an index register specified in the instruction encoding. That much is a fairly standard ...
10
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1answer
270 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 ...
9
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4answers
1k views

Compaq Portable vs IBM 5155 Portable PC

In 1983, Compaq introduced its first product, a portable computer weighing 28 pounds; 128-640K RAM, two 5.25" floppy drives, 9" monochrome CRT for $3590. It was extremely successful in the market, and ...
9
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2answers
410 views

Cleaning buckling spring keyboards

How do you clean keyboards with buckling springs? I have mentioned in an earlier question that I've recently bought an IBM keyboard but how do you clean a keyboard with buckling springs? I only know ...
9
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2answers
532 views

Desk computer with embedded CRT, 8" floppy

Back in 1981, my high school's computer classes were something like Computer Programming I and II, which taught BASIC on the Apple ][+, and a Computer Programming III class. In the III class, a ...
9
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3answers
966 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 ...
9
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2answers
918 views

Can I use my IBM P/N 93F0502 (circa 1992) monitor in a dual monitor setup with my modern Mac Mini or Thinkpad?

I have an old IBM monitor here and I'd like to use it as a second screen to my computer (Mac mini running Fedora or Thinkpad running Archlinux). I plugged it into the electricity socket without a ...
9
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1answer
3k views

How to tell if glue or electrolyte leak from old capacitors?

I recently acquired an IBM 5154 EGA monitor that works pretty well. The only minor problem is that the screen is slightly off-center. I decided to take it apart to adjust it, but discovered that many ...
8
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1answer
1k views

Is a Heatsink Needed for an Intel 80286?

I noticed my IBM XT 286 has no heatsink on the CPU nor a fan of any kind (only the PSU has a fan). I realize this was fine when it was built, but for longevity purposes, should I put a heatsink on it? ...
8
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2answers
918 views

When was DEFUN added to Lisp?

I don't see DEFUN in a ~1966 copy of PDP-6 LISP. I do see it in a 1972 Maclisp. AI memo 116A from 1967 doesn't have DEFUN. (It does have MACRO.)
8
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3answers
904 views

Choosing a VGA card for the IBM 5162?

When shopping for a VGA ISA card, how might I know if it would be compatible with an IBM 5162? Do all 8-bit and 16-bit ISA VGA cards work, or only some?
8
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1answer
749 views

How was the Traf-O-Data 8008 simulator developed?

Traf-O-Data was the first business partnership between Paul Allen, Bill Gates and Paul Gilbert. In order to develop the software for their custom-built Traf-O-Data machine (Intel 8008 Inside™), ...
8
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1answer
325 views

What is the purpose of the "difference of absolute values" instruction?

The IBM NORC computer, among others, had an arithmetic instruction computing the difference of the absolute values of its operands (|x|-|y|, see NORC Programming Manual, page 11, opcode 28), which ...
8
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1answer
532 views

Typical mid-scale business computer system of the late 70s

What was the most common business computer system of the late 70s, just before the Apple II and CP/M really started proliferating? For concreteness, let's say we are talking about a U.S. company on ...
8
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0answers
533 views

How can I open an IBM G50 CRT monitor?

First off, I know CRTs are dangerous and I have opened and discharged multiple CRT displays before. I've got an G50 monitor that shows a picture for a second or two and then goes blank. If you power ...
7
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5answers
750 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 ...
7
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1answer
1k views

What programming languages were most commonly used on the AS/400 in the 90s?

The IBM AS/400, formerly known as System/38, subsequently known as i (sic), is remarkable in being essentially the most future-proof of all the minicomputers, thanks among other things to the use of ...
7
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1answer
317 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-...