Questions tagged [ibm]

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

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1answer
377 views

Power switch color on IBM PS/2 red vs white?

Why do some IBM PS/2's have a red switch, while others have a white switch? Does the red or white power switch on the power supply signify something about the model number, CPU, or options that the ...
5
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1answer
279 views

Looking for an IBM multimedia demo from the 80s/90s about "Ulysses"

I am trying to identify / find an online copy of a multimedia technology demonstration video. Timeframe: late 1980s / early 90s? Source: IBM. Format: VHS. The content of this video was a computer ...
5
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0answers
96 views

IBM terminal schematics

I'm searching for the electronics schematics for IBM terminals 3477 and 3486. I've already googled for it without success. I've to mend this hw and the power side seems ok but doesn't function, so I ...
4
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2answers
3k views

Replacing cord for IBM model M keyboard

I bought a model m keyboard for use at work. The keyboard functions fine, but the cord is in bad shape. Functionally, the cord does not cause any shorts, but the plastic is very brittle and large ...
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 ...
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 ...
6
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1answer
283 views

The IBM RAM with non-standard pin layout

One and half decade ago I had an black IBM Thinkcentre tower. The specs were: Pentium 4 2.66 GHz 256 Mb IBM RAM (which later got upgraded into 512 Mb RAM), 40GB HDD, XP Pro SP3, GeForce 2 MX 400. ...
31
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2answers
3k 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 ...
9
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2answers
520 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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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 ...
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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1answer
300 views

XT IDE causes BASIC not to load properly on IBM 5155

I recently picked up an XT IDE. It works fine for the most part, but when I tried to load BASIC samples from the original IBM DOS 1.1 floppy(I was booting from it), the system hung up, only showing a ...
4
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1answer
301 views

IBM 650 - how many logic gates?

How many logic gates did the IBM 650 have? I'm used to measuring the complexity of a CPU by transistor count, but the 650 was a vacuum tube machine; the number of tubes would also be an interesting ...
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 ...
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 ...
9
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3answers
965 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 ...
3
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1answer
289 views

In IBM SCRIPT/VS, what does DSM stand for in macros DSMFIG, DSMLIST

In (S)GML ancestor's IBM SCRIPT/VS, what does DSM stand for in macros DSMFIG, DSMLIST... ?
3
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1answer
440 views

How did overstriking on printer terminals work?

The technique of creating special characters by overstriking i.e. superimposing two characters on top of each other was common on typewriters. This was carried over to printer terminals and was used ...
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 ...
5
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1answer
337 views

IBM AS/400 connection via SNASW on Cisco Router

TL; DR: How can I connect two old AS/400 machines via SNA when the only transport mechanism between the physical locations is IP? AnyNet isn't an option, see below. A friend of mine and I have two IP ...
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 ...
4
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1answer
687 views

Can I install DOS version 6.22 straight from IBM BASIC?

I accidentally deleted my previous version of DOS on my IBM model 8525. I was messing around with it, not knowing much of DOS, and now I'm back to using "IBM BASIC". Would I be able to ...
4
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1answer
206 views

My floppy drive in my IBM model 8525-001 doesn't seem to be working

I tried to put a floppy disk into my IBM model number "8525-001" and it doesn't seem to be processing it. The light below the floppy drive blinks yellow every once in a while (such as when I turn ...
6
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4answers
770 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 ...
7
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5answers
748 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 ...
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 ...
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2answers
4k views

How to connect c3270 terminal with hercules emulator?

I would like to get working with IBM System/360 on the Hercules emulator. I use a mac. With macports I have installed Hercules and c3270. Through this site: Running the IBM OS/360 MVT operating ...
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? ...
11
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1answer
645 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 ...
5
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2answers
350 views

How to debug BIOS ROM incompatibility?

I'd like to use the XT-IDE Universal BIOS with an IBM XT 286 (5162), but it's known to be incompatible. With the card installed, it will not boot from a floppy from which it would otherwise boot (it ...
4
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1answer
285 views

Does a final version of the IBM VGA XGA Technical Reference Manual exist?

I'm doing some bare metal programming and I'm getting a lot of information from the IBM VGA XGA Technical Reference Manual May92 document. The only reference I can find about this document, is this ...
8
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3answers
892 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?
4
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0answers
210 views

Are there alternative BIOS ROMs for the IBM 5162?

This page references a problem with the IBM 5162 BIOS where it will present an error during POST under some circumstances and that using a third-party BIOS was a workaround. What other BIOS ROMs ...
8
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1answer
742 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™), ...
14
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1answer
730 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 ...
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 ...
4
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1answer
318 views

Cyrillic Ж on IBM 1620?

Wikipedia says that The IBM 1620 Model I used the Cyrillic character Ж (pronounced zh) on the typewriter as a general purpose invalid character with correct parity. The Model II used a new character ❚...
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 ...
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 ...
8
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1answer
531 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 ...
9
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2answers
907 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 ...
5
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1answer
418 views

IBM Model M2 stuck on Scroll and Caps Lock, no keys reacting

Today I tried out an old M2 for the first time with an USB/P2 adapter. For the first 10 minutes it worked fine. Then I set it aside on my desk, left the room for a second, came back and suddenly the ...
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 ...
8
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0answers
526 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 ...

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