Questions tagged [ibm-pc]

For questions about the early IBM PC, clones and compatible systems.

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22
votes
10answers
4k views

Why was hardware diversification an asset for the IBM PC ecosystem?

The IBM PC was cloned very early on, and many third parties made hardware peripherals. This required users to run an OS, install drivers, manage IRQs and hardware bus addresses, etc. Why was this a ...
6
votes
1answer
203 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. ...
39
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8answers
9k views

Why weren't bootable game disks ever common on the IBM PC?

While for other platforms of that era (primarily, Amiga), putting a game on a bootable disk was quite a normal practice, this approach never taken off on IBM PC. Why not? I do remember people having ...
47
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2answers
7k views

On DOS computers, what would the PARK command do?

In 1994 or so, we had an old computer at my primary school. I remember finding out that it had a park command. From reading its documentation, it said that this command should be executed prior to ...
7
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3answers
320 views

What was the standard size of a PC clone's badge indent?

Generic beige-box PC clones like the ones pictured here often had an indent for the manufacturer's badge to be stuck on. Were these all a standard size, and if so, what were the dimensions?
7
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1answer
277 views

AT system without -5v

I have recently built a 80386 system. Lacking any AT PSU I connected a PicoPSU using an ATX->AT power adapter. Only card connected was a gpu (Trident TVGA 9000i). System performed BIOS checkup ...
6
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1answer
1k views

What was the first third-party commercial application for MS-DOS?

What was the first third-party commercial application for MS-DOS intended for IBM PC-compatible computers?
13
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1answer
5k views

What is the oldest commercial MS-DOS program that can run on modern versions of Windows without third-party software?

What is the oldest commercial MS-DOS program that can run on modern versions of Windows (such as Windows 8.1 or Windows 10) without third-party emulators?
6
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4answers
1k views

High-end PC graphics circa 1990?

I remember CAD being a major driver for PCs with high-end graphics cards; specifically AutoCAD was rising quickly in popularity around 1990 as PCs were able to compete with very costly CAD ...
2
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2answers
125 views

ISA Extension cards using more than 64kB

Related to my previous question around VGA framebuffer being limited to 64kB I started to wonder if there was any extension cards (or similar) using more than 64kB of address space in linear fashion, ...
6
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3answers
1k views

Why VGA framebuffer was limited to 64kB window?

VGA framebuffer was fixed to 64kB at A0000h. Right after that there’s MDA/CGA framebuffer at B0000h. I am not sure, but I recall VGA did have to support CGA and its framebuffer, but was there any ...
43
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5answers
15k views

What did the 'turbo' button actually do?

I remember the computer I played Commander Keen on as a child had a turbo button that I was forbidden to touch, what did this button actually do?
9
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2answers
452 views

How to use ISA card in modern PC

(Posted this on HW Rec but got no responses.) Would like to use an ISA expansion card in a modern PC. There are Expensive PCI - ISA adapters (but I cannot find any actually for sale now) USB-ISA ...
20
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4answers
4k views

What were wait-states, and why was it only an issue for PCs?

PC compatibles in the 1980s were often advertised as having zero, one, two, or sometimes more "wait states". Zero wait states was the best. Basically, the wait-states I am asking about are due to the ...
6
votes
1answer
269 views

When did MS Windows get Dual Monitor support?

I remember one of the features I admired on the Macintosh in the late 80s was support for multiple displays. First time I saw this was on an SE/30, using the internal display along with a big external ...
1
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2answers
267 views

IBM PC memory map - why RAM at the bottom?

The 8088 provided an address space of one megabyte. The IBM PC allocated that address space as 640K RAM (not that the 5150 could physically take that much, but the address space was allocated) ...
1
vote
1answer
117 views

Why did CGA RGBI output leave DAC to the monitor?

CGA on the original IBM PC produced sixteen colors, one bit each for red, green, blue and overall intensity modifier. The preferred output device was the later-arriving 5153 color monitor, which ...
6
votes
1answer
279 views

What's the fastest way to ignore keypresses?

I'm writing a game for the IBM PC (running MS-DOS), complete with fancy cutscenes. Unfortunately, though, the keys pressed during those fancy cutscenes are carried out once the fancy cutscene has ...
4
votes
4answers
249 views

Did the PC/AT-bus use its expanded address space?

The system bus of the IBM PC had 8 data lines and 20 address lines, in a logical correspondence to the 8088 CPU. The AT added a second inline edge connector to expand this to 16 data lines and 24 ...
4
votes
1answer
260 views

Did the 286 go out of its way to follow the 8088 bus protocol?

In general, different CPUs don't use the same bus protocol. A 16-bit CPU would not in general be expected to use the same protocol as an 8-bit CPU. For example, the 68000 would not be expected to use ...
3
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3answers
268 views

Gotek drives for MS-DOS (plus few more constraints)

I have installed two gotek device instead of two old unworking floppy disk drives (in particular on an Olivetti PCS 86). And the result is something like this: (The one on the right should the the A:...
13
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2answers
1k views

Which communication protocol is used in AdLib sound card?

By "AdLib sound card" I mean AdLib Music Synthesizer Card released in 1987. Wikipedia says that AdLib uses frequency modulation synthesis to produce sound, but does it use MIDI communication protocol ...
27
votes
3answers
5k views

Why separate cursor keys?

The original IBM PC keyboard didn't have separate cursor keys; the numeric keypad doubled as such. It wasn't long, however, until a new keyboard was introduced that did have separate cursor keys (so ...
11
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3answers
779 views

IBM PC expansion card latency

In the IBM PC and early successors and compatibles, it was commonplace for most of the computer's memory to be on cards in general expansion slots. (e.g. the original IBM PC could take 64K on the ...
6
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2answers
385 views

IBM would-be purchase of CP/M

It is well-known that on a sunny day in 1980, when the IBM representatives came knocking on the door of Digital Research, Gary Kildall was still in the air on the way back from visiting another ...
4
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1answer
205 views

Operating systems (on support or recent) to install on a i486 processor computer [duplicate]

What operating systems would you recommend for this type of hardware? Though I keep the question text generic because answers can work for many others, but my specific case is a Laptop Siemens ...
38
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2answers
6k 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 ...
6
votes
1answer
384 views

How can I edit CMOS hard drive geometry settings on a 1991 PC?

First, I am NOT asking how to use the BIOS Setup utility. I'm asking how to OVERRIDE the built-in settings my BIOS Setup supports for the HD geometry. I have a 1991 NCR PC with a 386SX, on-board IDE, ...
43
votes
2answers
11k views

Who set the 640K limit?

We all know that "640K should be enough for everyone". But who actually set this limit? The quote is often attributed to Bill Gates, but it doesn't seem like a decision for an Operating System vendor ...
5
votes
1answer
627 views

Microsoft Flight Simulator 1.0 “DIVIDE BY ZERO” command

I was reading an Wikipedia article named "History Of Microsoft Flight Simulator" and I noticed something weird about Microsoft Flight Simulator 1.0: November 1982 sometime during 1981-82 ...
45
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10answers
8k views

Why was preemptive multitasking so slow in coming to consumer OS's?

Preemptive (rather than cooperative) multitasking was a highly-touted feature for PC's in 1996, with its inclusion in Windows 95 for the first time. It was also highly-touted for 2001 Macs when ...
35
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7answers
8k views

How did Apple fail to tap the business and scientific markets?

Currently reading an excellent book called Blue Magic: The People, Power and Politics Behind the IBM Personal Computer, which is just what it says on the tin; highly recommended to anyone who wants to ...
23
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8answers
3k views

What were the early PC applications requiring a hard disk?

I had to wait about 5 years before hard drives (HDs) became affordable enough to begin moving off of floppies. During this time, I remember my desire for an HD being based on convenience. All the ...
21
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2answers
2k views

The almost-was Atari IBM PC

One of the more remarkable events in the history of personal computers was IBM contemplating basing their PC on Atari technology. That this was seriously considered, everyone agrees, but it's hard to ...
31
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18answers
10k views

What were the real competitors to the early IBM PC?

As I understand it, PC was not really competitive with Home computers until the 90’s. The PCs rise in popularity in the 80s must have been mainly in the business world. So during that time, what ...
16
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2answers
2k views

How do CGA emulators for Hercules graphics work?

HGC cards on IBM PCs used to be able to run CGA software by using a CGA emulator. How exactly did those programs work? What were the limitations?
5
votes
3answers
554 views

What was the first integrated PC compatible computer?

When IBM developed the PC, they famously chose a bunch of off-the-shelf components. Besides making the machine relatively easy to clone, another effect of this was it used a lot of chips and board ...
3
votes
1answer
240 views

Using floppy disk interface on Future Domain TMC-1680 SCSI ISA card

I have this old card, a Future Domain TMC-1680 ISA SCSI card that has a 34-pin floppy disk connector on it. I am trying to research that to see if I can make it work (before anyone asks - just for the ...
3
votes
1answer
313 views

IBM 5153 monitor vertical resolution

The IBM 5153, the color monitor accompanying the original IBM PC, was designed to work with the CGA graphics card, vertical resolution 200 scan lines. This was quite unsurprising and straightforward. ...
6
votes
4answers
3k views

How do I create a boot menu to select between Windows and DOS?

I was not a PC user before Windows 98. But I remember one of my friends was using a boot menu in his 486 machine to select between Windows/DOS. The menu was like: 1. EMS 2. XMS 3. Windows If we ...
11
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3answers
1k views

What specific technical advance(s) allowed PCs to play “Full-screen full-motion” video?

In the early 1990s, the new buzzword for PCs was "Multimedia", and the gold standard for multimedia performance usually talked about was "full-screen full-motion" video playback. Many will remember ...
6
votes
5answers
468 views

Where are the authoritative specs for legacy PC/AT devices still in use in today's PCs?

For example, the 8250/16550 chip used to handle serial communication is still simulated by modern chipsets and is enumerated by ACPI as PNP0500/PNP0501. You can find datasheets for these chips. ...
7
votes
1answer
242 views

How did Drive Overlay programs break BIOS disk barriers on older PCs?

I was just reading a thread on Vogons about OnTrack and EZ-Drive setup, and it occurred to me that I have no idea how they work. Please explain why the barrier existed and then how the overlay ...
6
votes
1answer
513 views

First 80286 Based Computer

The 80286 was released in early 1982. The IBM PC AT, which used it, was released in late 1984. Two and a half years is a long time to design a new computer that is a fairly modest upgrade on existing ...
9
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2answers
1k views

Unused RAM Chips on x86 machines

On classic x86 machines the upper 384 KB of system memory contains video RAM and BIOS ROM Besides other things. Those areas overlay over conventional RAM, so that you can't use all upper memory, but ...
4
votes
2answers
560 views

Is there really 1MiB of physical memory in the motherboard of a PC AT/XT?

This is a question that has been puzzling me for a while. What happens with devices like graphic cards that have their own memory chips? Do these cards read/write from their own internal memory to/...
1
vote
4answers
904 views

What we commonly call PCs are in fact ATs, correct?

I remember all those video game boxes stamped with IBM PC (and compatible), while bringing good memories I felt this was rather incorrect. Most of these games would never run on such computers, i.e. ...
2
votes
1answer
127 views

Thinkpad 350 keyboard

Am wondering how to use the keyboard from a Thinkpad 350. There are three cables, with 6, 10, and 18 pins (but the big connector on the motherboard seems to have only 17). I assume this is a grid of ...
18
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2answers
4k views

First commercial DOS game?

What was the first commercial game sold for use on IBM/MS/PC DOS after the IBM August 12, 1981 release.
6
votes
2answers
563 views

Who were the first engineers to “cleanroom” the IBM PC BIOS?

In the first season of the AMC show Halt & Catch Fire, the protagonist "Cameron Howe" is introduced. Cameron portrays a rookie engineer who is recruited for being extraordinarily talented, and is ...