Questions tagged [ibm-pc]
For questions about the early IBM PC, clones and compatible systems.
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What's the Norton SI of my new PC? [closed]
In the field, the benchmark I used everywhere was the Norton Utilities Sysinfo Benchmark.
It measured computer power in units of IBM PC horsepower. So the 8088 PC got an SI of 1. The AT had an SI of ...
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What is this PSU connector? Compaq Portable motherboard
I've lost the PSU wiring harness to my Compaq Portable motherboard in a move and I'm trying to figure out what connector this is. Here's a picture with some AT-era Molex connectors for perspective.
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What's the earliest source for the legend of Gary Kildall's airplane snub?
A commonly repeated (and commonly debunked) legend describes how Gary Kildall blew his chance at writing the operating system for the IBM PC. Examples include the following:
…legend has it that ...
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Can someone explain the logic behind Pause and Print Screen modifiers?
Firstly, do I have a correct understanding of what these keys do?
On the Wikipedia SysRq page, it says that the Alt key must be held down to invoke SysRq. On the BIOS interrupt call page, it says ...
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When did the PC bus start slowing access to video RAM?
The PC architecture, from the original IBM PC onward, has always been designed around the idea that video memory will be on an expansion card. This was an unusual design decision; most 80s computers ...
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Why didn't PC games eschew MS-DOS and deal with BIOS directly?
Given the memory referencing limits of MS-DOS for compatibility purposes, why didn't games produced for the 286+ processors eschew MS-DOS and talk directly with the BIOS or IO hardware, instead of all ...
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How can I reverse-engineer the game Wizardry (1981) for PC, based on UCSD Pascal?
I am looking at the files included with the 1981 game Wizardry. The particular version I have is from a 1998 re-release, but I do not know if the binary is still the original 1981 release.
My ...
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Were there Any Applications Making Explicit Use of the MDA's Colour Capabilities?
The first series of MDA adaptors for the IBM PC had the ability to show colours according to the attribute byte, much like the CGA does in text mode, but I don't remember any PC application that ...
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What was the purpose of the “key” pin of the P8 connector of the IBM PC PSU, and why was it changed to +5V with the AT?
According to the IBM PC/XT Technical Reference page 3-6, pin 2
of plug P8 is a "key." (Note that this is the pin specifically; this is
separate from the keying of the shroud, which is ...
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Were there any PCs where you could switch Turbo Mode via the keyboard?
All the PCs I have personally used or encountered which had a "Turbo Mode" (clock frequency switch, with frequencies in the 5-25MHz range) did this via a hardware button similar to the reset ...
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How to treat an old PC
I have an old IBM PS/2 30/286, now sitting for a while on one of my desks.
I'm a bit afraid that it will stop working sooner or later, so what's the best way to keep it 'alive' ?
I fire it up every ...
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Were VGA palette's HSV math properties used in practice?
In "Why were those colors chosen to be the default palette for 256-color VGA?", we've established that 216 of its colors represent a 24x3x3 truncated HSV color space.
This results in an ...
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Why weren't CGA colors selectable from palette?
Most memorable graphics mode in games for CGA was 320x200 which supported 4 colors. (I know there was 16 color composite mode trick, but let's ignore that.)
Those 4 colors could be selected from ...
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Why were those colors chosen to be the default palette for 256-color VGA?
Although subjective, I believe I'm not the only one considering default VGA 256 color palette to be hideous and ugly.
What is the story behind this, why were these particular colors chosen?
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Was there a notable mainstream 640×480 monochrome display for PC earlier than MCGA
On IBM PC compatibles, the first widely-known display subsystems capable of displaying 640×480 pixels (resulting in square pixels with a 4:3 display) were the MCGA and VGA in 1987. By then, 640×400 ...
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