Questions tagged [ms-dos]

For questions regarding MS-DOS, the Microsoft Disk Operating System, and its batch scripting language. Do not use this tag for questions about DOS batch languages in general.

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What key factor led to the sudden commercial success of MS Windows with v3.0?

Microsoft Windows was originally introduced in 1985, ostensibly to compete with the Apple Macintosh, and other computers shipping with graphical shells by that time. However, early versions of Windows ...
80
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2answers
12k views

How did Windows 3.1 implement multitasking?

Windows in its earliest days was simply a shell that ran on top of MS-DOS, which means that Windows 3.1 itself was actually just a standard MS-DOS application like any other. Yet, MS-DOS is not a ...
65
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3answers
13k views

What character is the MS-DOS cursor?

The cursor used on my 486 (and Pentium 3) in MS-DOS 6/7 has a thick underlined character. I cannot find that in code page 437. The underscore character is the closest to it, but is thinner. Where ...
61
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3answers
12k views

Why did DOS use dollar-terminated strings?

According to a few tutorials I am seeing, DOS used dollar-terminated strings to write to the terminal. This seems to also be documented here on INT 21H. AH = 09h - WRITE STRING TO STANDARD OUTPUT ...
60
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3answers
19k views

Why is Windows using CRLF and Unix just LF when Unix is the older system?

Windows and MS-DOS use for new lines the control characters CR-LF (carriage return, line feed), while unix uses just LF. As far as I know CR-LF made sense for systems controlling an real teletyper, ...
56
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7answers
9k views

Why did the MS-DOS API choose software interrupts for its interface?

Access to the DOS API was done through the INT 21h x86 instruction. This was always counter-intuitive to me, coming from 8-bit systems that accessed system services by calling subroutines through a ...
47
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1answer
10k views

What is the context of the button “Is MS DOS a feminist?”

I just saw this button in the Computer History Museum, and I'm wondering what is the context? Context removed, "Is MS DOS a feminist?" is about the most non-sequitur thing I've seen.
46
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8answers
10k 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 ...
44
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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 ...
39
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8answers
11k views

Is DOS being shipped with or as an installed OS?

Given the very small size of DOS, it would seem it might still be ideal for some applications such as handheld games. Is any system manufacturer still shipping DOS with their machine? If no one is ...
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10answers
8k views

Is there a reason to prefer earlier versions of MS-DOS over later?

I understand MS-DOS to be backwards-compatible, so is there a reason to run a version earlier than the last (6.22) on an old computer? The only reason I can think of would be for period-accuracy, but ...
33
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8answers
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How to put a delay in AUTOEXEC.BAT

I have this MS-DOS 6.22 machine which maps a network drive to a SAMBA share on a Raspberry PI. The PI is powered by a USB lead from the DOS machine, so the two power up together. The mapping starts ...
33
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3answers
4k views

How did Windows ME “cripple” DOS?

Windows ME includes the ability to create a bootable DOS floppy. This floppy contains versions of COMMAND.COM and IO.SYS that are "crippled" to remove real mode. This is done with only one changed ...
33
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1answer
3k views

Where and what was Haunt.bat? A game pre-loaded on a c1992 PC

This doesn't belong on the gaming SE, so I'm trying my luck here. I'm looking for any info I can get on an old game that I simply known as "Haunt.bat". Here is the back-story: In the mid 90's a ...
32
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4answers
5k views

Why was 'echo on' chosen as the default setting within batch scripts in MS-DOS?

In my experience, just about every single MS-DOS (and thus Windows cmd) batch file starts with the line @echo off, to silently switch off echoing of the commands in the batch file to the console. This ...
30
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1answer
3k views

Did DOS zero out the BSS area when it loaded a program?

As an example, say we have a DOS MZ EXE file that's around 20 KiB in size. The EXE header contains the value 0x1400 at offset 0x0A indicating that the program is requesting 5,120 paragraphs (or 80 KiB)...
29
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5answers
8k views

Are MS-DOS and Windows 9x vulnerable to Meltdown?

In an interesting crossover between current events and Retrocomputing, the vulnerability known as "Meltdown" was publicly disclosed on January 3rd 2018. The retro-computing tie-in is that this ...
28
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3answers
8k views

Were 9.2 file names possible in MS-DOS?

In MS-DOS (and FAT16), you could only have 8.3 file names (like QUESTION.TXT) with only single-case letters and numbers (and a few symbols). The MS-DOS Editor also defaulted to 8.3 - typing edit ...
28
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4answers
4k views

What's the relationship betweeen MS-DOS and XENIX?

Browsing MS-DOS sources on GitHub, I often see mentions of XENIX: DOSSYM.ASM: ; XENIX calls all return error codes through AX. If an error occurred then the ; carry bit will be set and the ...
28
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1answer
2k views

How does the command.com shell work with MS-DOS?

On my systems that are running MS-DOS, I change the default command.com to 4DOS for more features. How was the shell system designed and how did it with the operating system in MS-DOS that it enabled ...
28
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2answers
3k views

How did MS-DOS assign drive letters in the case of more than two floppy disk drives?

The IBM PC BIOS had provisions for up to four floppy disk drives, by virtue of returning the number of floppy disk drives in a two-bit field plus a none/some flag (allowing for reporting values of 0, ...
27
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4answers
4k views

Why wasn't DOSKEY integrated with COMMAND.COM?

Why did Microsoft make DOSKEY a separate command, instead of integrating it with COMMAND.COM? I don't think DOSKEY uses a lot of RAM or was useless in the '80s... Maybe there was another reason not ...
27
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2answers
11k views

Looking for PC graphics demo software from the early 90s called “Unreal”

Back in the early 90's I remember downloading a graphics demo called, I think, "Unreal". This was on DOS on a standard PC and probably downloaded from a BBS. Identifying information: It ran for ...
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5answers
5k views

Why are Windows 95 installation disks not uniquely bound to a single product key?

I was installing the OEM version of Windows 95 on VirtualBox the other day for reminiscence sake, and for some reason I had two different product keys. I tested both of them to see which one mapped to ...
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9answers
6k views

What other tricks were there to get more data onto floppy disks?

I remember using a utility back in MS-DOS 3.3 days, called MAXI Disk, that somehow magically managed to get 420K on a 360K 5¼″ disks. I assume it managed it by destroying some redundancy like a backup ...
25
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3answers
4k views

Where did DOS store graphics fonts?

I remember using a wysiwyg print program called Fontasy for CGI graphics in DOS because of a lack of standardized graphics fonts. Companies were selling "font packs" for other type fonts. Prior to Win ...
24
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3answers
5k views

Why does DOS ask for the current date and time upon booting?

In most versions of DOS, when they are started from a medium that lacks an AUTOEXEC.BAT file, the very first thing COMMAND.COM does is ask the user to confirm the current date and time: Starting PC ...
23
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4answers
8k views

Is there a simple way to display ANSI art and animation files in a modern terminal window?

ANSI art and animations were prevalent on BBS systems in the late 80s and early 90s, and the ANSI art scene continues to thrive today. There are thousands of ANSI art files, with usual extension .ans, ...
22
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10answers
3k views

Why did CP/M and MS-DOS use the BIOS instead of their own drivers to access hardware?

Modern versions of Windows (and other modern operating systems I suppose) have their own drivers to access hardware. But as I have read, in the old days, if CP/M or MS-DOS wanted to access hardware, ...
22
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9answers
6k views

Why does the single dot entry exist in file systems?

There is plenty of literature about its meaning, the current directory, but I would like to ask about why such thing do exist in first instance. While CHDIR .. usefulness is obvious, i.e. go to the ...
21
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5answers
8k views

Will PC-DOS run faster on 4 or 8 core modern machines?

When I run PC-DOS on my 4 core AMD Phenom chip, does it take advantage of the extra parallel CPU's? If not, is there a way to coax DOS to use all available CPU's or does this require specific ...
21
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2answers
1k views

What are these tiny TSRs doing?

I've been puzzled by this for a while now. The (very old) game Phantasie comes with three small TSRs that are run prior to running the main game executable. This is the content of the file PH.BAT, ...
20
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3answers
4k views

Did MS-DOS itself ever use blinking text?

I know that it was possible to create blinking text, but did the operating system itself (I mean, in output from functions of command.com and similar executables) ever make use of blink formatting? ...
20
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1answer
2k views

When was QDOS changed to MS-DOS?

So a while back, I heard that MS-DOS was originally named QDOS (Quick and Dirty Operating System), and that it was later changed is MS-DOS (Microsoft Disk Operating System). This was probably a ...
20
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1answer
836 views

Logo of a bow tie guy with a spoon

I was in the Computer History Museum in Silicon Valley last week, and I saw this badge. I know I've seen that logo somewhere before, but I can't remember where! Does anyone know where it's from?
19
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6answers
2k views

Sound driver for DOS or Windows 3.x that used the PC speaker?

Long ago in a galaxy far far away, back in the early 90's, I worked for a crappy clone company as a phone technician. At the time, 386SX/25's were common for in-house technical support / customer ...
19
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6answers
5k views

How can I emulate MS-DOS on OS X?

I am looking for a emulator for MS-DOS for OS X to run old games on. Are there any free emulators for MS-DOS that run on an Apple machine with OS X?
19
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2answers
1k views

Slash versus backslash as directory separator - what/who caused this rift?

MS DOS and derived systems use backslash \ for path separator and slash '/' for command parameters. Unix and a number of other systems used slash '/' for paths and backslash \ for escaping special ...
18
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2answers
6k views

Was OS/2 a viable alternative for daily DOS and Windows tasks?

After playing a bit with the OS, a question sparked my interest: Could it entirely replace DOS and Windows ? Let's restrict the scope of this question a bit since it's fairly broad, Was it ...
18
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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
1k views

Why did MS-DOS choose the percent symbol to designate variables?

I couldn't find anything but is there any reason for choosing % over $ like in *nix shells?
17
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3answers
4k views

Do you need to allocate memory before you use it in MS-DOS?

In modern operating systems (for example: Windows), you can't access a memory location before you allocate that memory location to your program (or else a segmentation fault will occur). I am ...
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
1k views

Why did ScanDisk exist?

As far as I can tell, CHKDSK has been part of DOS and Windows since day one. However, in later versions of DOS, CHKDSK was shipped along side ScanDisk. As of Windows 98, running CHKDSK will result in ...
17
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2answers
3k views

Name this PC DOS Combat Flight Simulator

I'm trying to remember the name of a PC DOS Combat Flight Simulator that I played around 1991/92. I can give the following details: It was named after a US fighter plane that would have been in ...
17
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1answer
3k views

How did large .COM files work?

An MS-DOS .com file is just raw code/data without header, thus no linking information, and was limited to be loaded into just one segment (64kB). That's the reason corrupted binaries would print "...
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 ...
17
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2answers
1k views

What is the difference between DriveSpace and DoubleSpace?

DriveSpace is the successor to DoubleSpace. Both are DOS systems that mount a Compressed Volume File as a drive, allowing ordinary programs to interface with a compressed drive without an intermediate ...
16
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5answers
2k views

What tools were used in late MS-DOS era for reverse engineering and patching binary executables?

In the late MS-DOS era, what were the state of the art software tools for reverse engineering and patching binaries, i.e. .exe and .com files? A simple list of the tools that were "state of the art", ...
16
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4answers
2k views

What are my options for multitasking in MS-DOS 5.0 on an 80186 with EMS?

I've got an HP 200LX, which runs DOS 5.0 from ROM, and I'm using EMM200 to provide some EMS from the C: RAM disk (it uses the memory controller to directly map the "disk" blocks into memory, and thus ...