Questions tagged [ibm-pc]

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

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18
votes
2answers
5k 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.
18
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3answers
3k 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?
18
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2answers
2k views

What was the first C compiler for the IBM PC?

When did a C compiler first become available for the IBM PC? I have fond memories of Turbo C, but that didn't become available until the mid to late eighties; it definitely wasn't the first one. ...
17
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5answers
5k views

What is most appropriate choice for DOS for a 1990 80386 PC?

I plan to install Windows 3.0 and PC/GEOS on top of DOS. Plus I will install numerous games from the 1984-1992 timeframe. Some of the later games will require >640K RAM and make use of an EMM driver. ...
17
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4answers
2k views

80286 real mode emulator for 8086

While trying to use a "modern" sound card (an Aztech Sound Galaxy Pro 16 II) in an XT compatible 8086 computer, I encountered the problem that the drivers and tools (like the mixer initialization tool ...
17
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3answers
2k views

How did DoubleDOS work?

Back in the MS-DOS days, there was a program DoubleDOS that you could run that would split your machine in half and multitask two separate DOS programs. While it didn't particularly work well for ...
16
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6answers
4k views

What PC “Clone” technology standards were introduced by clone manufacturers?

IBM famously created the PC standard with the introduction of the first IBM PC in 1981. IBM also extended the standard with the introduction of the PC/AT (1984) and the PS/2 line (1987). However, by ...
16
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5answers
3k views

Adding the third floppy drive?

I've seen a few computers with more than two floppy drives, most with two 3.5" and one 5.25". My question is how was this achieved? I've heard that it could be done with a second controller card, but ...
16
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5answers
4k views

What was the first multiprocessor x86 motherboard?

I know dual socket motherboards were around in the 90's before Intel released the Core series. And SMP hardware and operating systems have been around earlier than the PC platform of course. ...
16
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2answers
2k views

Why did the 8087 need a special socket?

The IBM PC included a coprocessor socket for the 8087 floating-point unit. Logical enough; some customers wanted to use the 8087 to make numeric calculations run faster. But why was the 8087 designed ...
16
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5answers
2k 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 ...
16
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3answers
2k views

How did the IBM PC handle multiple physical devices serving memory at the same physical address?

I'm trying to figure out how the IBM 5150 PC handled the case where multiple physical devices (memory chips) were mapped to the same address within the 8088's physical address space. The closest I've ...
16
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4answers
15k 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 ...
15
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7answers
6k views

Why did the IBM PC have an internal power supply?

Microcomputers run off low voltage DC, but usually came with a power supply to produce a suitable DC current from the mains AC voltage. It was usual among early home computers to supply an external ...
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2answers
2k 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 ...
14
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6answers
2k views

Why did tactile-feedback keyboards lose popularity?

IBM spoiled me for hardware quality. I've gone through many computers, including a TRS-80, Heathkit H-89, Commodore Vic-20 and C-64, and countless PC's but my first original IBM PC will always be my ...
14
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1answer
6k 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?
14
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3answers
2k views

What are the electrical characteristics of a PC gameport?

I'm considering building some custom gizmos to connect to the gameport on my retro-hobby PC (SNES controller adapter, macro/turbo box, etc.) but I haven't been able to find much information on details ...
14
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1answer
1k views

What manages Upper Memory Blocks (UMBs) in MS-DOS?

I had always assumed that EMM386.EXE was responsible for managing the Upper Memory Blocks - UMBs - the memory space between 640KiB and 1MiB in real mode x86. For example, on MS-DOS 6.22, help emm386....
13
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4answers
2k views

Were there VLB cards other than video cards and SuperIO controllers?

VESA local bus was an expansion bus used to overcome speed limitations imposed by ISA bus. In theory VLB could reach 1280 Mbit/s (with 40 MHz CPU) which was way more than ISA's 66.7 Mbit/s. The speed ...
13
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3answers
1k views

PC/AT two DMA controllers - what is the purpose of cascade channel and how did it work?

Why did the design need to reserve one channel for cascade, how did it work and what exactly was going on there?
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3answers
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Only “Drive A:” detected with two floppy disk drives

I am trying to repurpose an old Acer Aspire M1641 to copy/format bulks of 3.5'' floppy disks. I think it's one of the last generations of computers to have a 34 pin floppy disk drive header as it also ...
13
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1answer
488 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 ...
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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 ...
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3answers
2k views

What was the second most common incompatibility in MS-DOS machines? [closed]

When the IBM PC was released, it did not take long for people to figure out that there would be a big market for compatible machines. The first wave relied on MS-DOS as the compatibility layer. The ...
12
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3answers
927 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 ...
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2answers
1k views

Hard coded hard drive BIOS geometries

Most old BIOSes on PCs and compatibles provided means to enter hard drive geometries (cylinder/head/sector as well as more esoteric things like write precomp) when configuring the machine. Some (AMI ...
11
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2answers
3k views

Are BIOS ROMs interchangeable among different vendor's PCs?

For PC/AT, 80386, and 80486 machines from the late-1980s through early 1990s (e.g. retro machines, not modern), can you expect to pull a BIOS ROM from one machine and have it work fine in a different ...
11
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3answers
1k views

Default (as opposed to physical) read/write heads - what are they?

The Seagate U Series hard disk Product manual states that the drive has 16 "Default read/write heads" while it has 4/3/2/1 "Physical read/write heads" (depending on actual model). ...
11
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6answers
1k views

When did the tower form factor appear and when did it become popular?

Essentially, my question is there in the title. Tower cases are commonplace these days, and probably are the "default" form factor for personal computers (or at least were, before they were surpassed ...
11
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3answers
4k views

Restore corroded AT motherboard with dead CMOS battery

I have acquired a nice MS-DOS PC from EET Computer (I couldn't find any information about them). It actually works, but I have two errors on boot: Floppy disk drive controller failure; CMOS Battery ...
11
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2answers
824 views

How can I read a 5¼″ drive on 1996–2007 equipment?

In my organization's archive I just found some 5¼″ floppies, presumably IBM PC 320/360k. They contain information that we have on paper, but I'd really like to have on electronic media, not least so ...
11
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2answers
1k views

Was natural convection ever a consideration in orienting expansion cards?

Many computers have followed the design pattern of a backplane with expansion cards, including arguably the three most influential microcomputers ever built: the Altair 8800, the Apple II and the IBM ...
11
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1answer
1k views

What is this old PC truck game?

I've begun to recall a game I played as a child with my brother, and I can't remember what it was called for the life of me. The reason I'm asking for identification is because I remember how much he ...
10
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2answers
11k views

Windows 98 / XP Dual boot

I have acquired an old Shuttle X PC (Windows XP, Mini-DTX form factor HTPC) that works fine. As I can't do much with this form factor (I can't fit a modern motherboard in the case) and that the ...
10
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2answers
732 views

When does an IBM-compatible PC keyboard controller dequeue scancodes?

There is a not-unheard-of technique in DOS software to detect certain keypresses (like Ctrl+Break) by intercepting the keyboard interrupt (IRQ 1) and reading the scancode directly from the keyboard ...
10
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2answers
711 views

What PC graphics tech outperformed Sega Dreamcast in 1999?

The Sega Dreamcast was released in 1999 (1998 in Japan) at just the time that the competition for 3D graphics on PCs was intensifying. It's my assumption that a high-end 1999 Pentium II PC with 3Dfx ...
10
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3answers
963 views

Transferring files between Commodore PET and IBM PC

Suppose you have two early eighties computers, a Commodore PET with 8050 disk drive and an IBM PC with its 5.25" disk drive. Is there a way to transfer files between them? Not machine code programs, ...
10
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1answer
741 views

Can the IBM PCjr be upgraded to support the better features of the Tandy 1000?

It is well known that the IBM PCjr was a commercial failure and that the Tandy 1000 series of computers not only matched the features of the PCjr (other than maybe the wireless keyboard), it also ...
10
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1answer
276 views

Did the Harris 80C286 differ from Intel's 80286 in its behaviour?

The Harris company, well known for being an early second source making x86 chips under license, eventually produced a fully static CMOS 80C286 of their own design (later known as the Intersil 80C286 ...
9
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6answers
7k views

Cannot boot from a Compact Flash card

I am trying to fix up an old work computer I have from the early to mid 90's. Everything works fine, but the hard drive makes a horrible clicking noise when it loads anything, so I decided to ...
9
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2answers
553 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 ...
9
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1answer
970 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, ...
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 ...
9
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2answers
901 views

Looking for a specific BASIC music program from the 80s

When I was a kid, we had a PC-XT with a lot of GW-Basic programs on it. I am trying to track down one in particular -- it was a music player of sorts. A menu (all monochrome text as I recall) and you ...
8
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2answers
765 views

Could CGA synchronize with vertical blank?

According to http://www.vcfed.org/forum/showthread.php?62049-The-myth-of-the-vertical-retrace-interrupt-on-EGA-VGA IBM first implemented a vertical retrace interrupt on the PCjr in 1984. That ...
8
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2answers
1k 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 ...
8
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2answers
2k views

Are game port joystick button circuits more than plain switches? Is this one just faulty?

I'm building a custom interface unit for a game port joystick. To use/test it, I have a CH Products Mach III. (This is the IBM PC version, not the Apple version.) I purchased the joystick for this ...
8
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5answers
569 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. ...
8
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1answer
561 views

Was there ever a functional EGA emulator for the Hercules graphics card?

I used to use a CGA emulator (don't remember which one it was), that could show some gfx even in EGA/VGA-only games (when I selected EGA mode). I remember my frustration seeing some garbled graphics ...