Skip to main content
50 votes

Why didn't PC games eschew MS-DOS and deal with BIOS directly?

You need to run the game somehow. There were some early booter games, but as soon as you had a hard drive, users typically want to store programs, including games, on the hard drive, as files. When ...
Justme's user avatar
  • 33.9k
43 votes
Accepted

Was the MS-DOS window in Windows 95 an emulator like current DOSBox?

No, running MS-DOS window in Win95 was nothing like DosBox. DosBox is an emulator, but Windows 95 ran DOS in a 16-bit process as virtual machine. DosBox is basically a C program that emulates all the ...
Justme's user avatar
  • 33.9k
33 votes
Accepted

Did any MS-DOS program ever use the System Request interrupt?

TL;DR: One of the great Ideas that never Materialized Contrary to what is often assumed, the key was not added to support some 3270-style emulation1, but to enable a basic multi-application/OS ...
Raffzahn's user avatar
  • 226k
32 votes
Accepted

Beep command with letters for notes (IBM AT + DOS circa 1984)

This sounds like the PLAY command in BASIC. It takes a string indicating what to play, with the following notation for the features you mention: A to G, followed by optional #, +, or -, plays the ...
Stephen Kitt's user avatar
31 votes
Accepted

How did 16-bit MS-DOS programs use a large (> 64KB) stack?

They simply did not use a large stack. If you look at the standard memory models for the x86, there was a single stack segment in all of them (which was even shared with other segments in the smaller ...
dirkt's user avatar
  • 28.3k
27 votes

Why didn't PC games eschew MS-DOS and deal with BIOS directly?

We need to look into this in a bit more detail. There were indeed a limited amount of "direct boot" games that completely by-passed DOS and implemented their own low-level hardware support. (...
tofro's user avatar
  • 35.2k
24 votes
Accepted

Is there a technical reason why Datel Action Replay on PC required a card?

Disclaimer: I always managed with Turbo Debug on games, which relied exclusively on software, and only used the amiga version of Action Replay. That said, the hardware Action Replay on PC gives it ...
Jean-François Fabre's user avatar
20 votes

Did any MS-DOS program ever use the System Request interrupt?

The SysRq key is a perfectly normal key on the keyboard. It does not generate a special or unique interrupt by itself. The standard keyboard interrupt of BIOS just does what it does for all keys and ...
Justme's user avatar
  • 33.9k
18 votes
Accepted

How does 2M for DOS (2 MB formatted floppy disks) achieve what it does?

A typical floppy disk track will contain, depending upon the exact medium, between 8 and 24 repetitions of the pattern "sector header, sector data; sector header, sector data", etc. Each ...
supercat's user avatar
  • 37.2k
18 votes
Accepted

DOS: How do I type an ANSI escape sequence?

[All of the examples have been tried using a real PC and DOS 3.20] TL;DR: Use a Batch File For Experiments The most simple way to start testing wold be a batch file providing the needed ESC character. ...
Raffzahn's user avatar
  • 226k
16 votes
Accepted

What problem does LOADFIX solve?

In short, it prevents a code bug from triggering in some executables compressed by Microsoft EXEPACK. Programs themselves are supposed to work at any address, but these executables are packed with ...
Justme's user avatar
  • 33.9k
15 votes

How can I reverse-engineer the game Wizardry (1981) for PC, based on UCSD Pascal?

A few hints about how the UCSD system works. What's often called UCSD-Pascal is in fact a stand alone OS with Pascal as one possible language. Others were BASIC, FORTRAN, Ada or Assembler. The whole ...
Raffzahn's user avatar
  • 226k
14 votes

How can I reverse-engineer the game Wizardry (1981) for PC, based on UCSD Pascal?

The background has already been explained, some additional details. I don't know where to get the version you have, but quick googling found a version with a 320K WIZ1.DSK. This one clearly is a UCSD-...
dirkt's user avatar
  • 28.3k
14 votes
Accepted

Is there any DOS game before Quake era (1996) that makes heavy use of the FPU?

MobyGames lists a number of games with support for a FPU¹. The earliest shown there are Falcon 3.0 and Scorched Earth (1991), and like most of the other games in the list, the FPU is optional: Note ...
Stephen Kitt's user avatar
14 votes
Accepted

What are the minimum system requirements to run GW-BASIC?

One thing you may want to look at. I remember encountering a bug in one of the Borland products in that they complained of being out of memory on a 640K, himem-aware, DOS 6.22 system. That was due to ...
paxdiablo's user avatar
  • 4,917
13 votes
Accepted

How can I make the Microsoft C compiler for DOS emit a loop with an intermediate jump to continue?

It turns out that in MS C 5.1, in addition to all the /O... options there is one seemingly unrelated one that influences the optimizations for this compiler: /Zi. In the output of CL /help it is ...
neuviemeporte's user avatar
13 votes

How did 16-bit MS-DOS programs use a large (> 64KB) stack?

DOS programs typically have limited stack requirements, and tend to declare small stacks. DOS itself uses its own stacks in many cases, and programs’ stacks don’t need to leave much room for DOS use. ...
Stephen Kitt's user avatar
13 votes

Can DOS make use of more than 640 KB of conventional memory on 80186?

Yes, you can have more than 640KB of conventional memory in some DOS. FreeDos already seems to work for you, as you have 704KB of conventional memory according to MEM. And apparently an IBM 5150 with ...
Justme's user avatar
  • 33.9k
12 votes

How can I reverse-engineer the game Wizardry (1981) for PC, based on UCSD Pascal?

What an intriguing piece of archaeology you've stumbled upon! COM programs, present an interesting quirk. Despite its code segment being confined to a mere 64KB, they allocated all available free RAM ...
Rui F Ribeiro's user avatar
12 votes
Accepted

Can DOS make use of more than 640 KB of conventional memory on 80186?

Yes, you can. Normally if there is RAM at A0000 there should be no issues. I used to do it all the time with my PC-Speed emulator on the Atari ST. As all the UMA holes were filled with the RAM of the ...
Patrick Schlüter's user avatar
12 votes

Is there a technical reason why Datel Action Replay on PC required a card?

Jean-François Fabre’s answer mentions a number of advantages of a hardware solution over software, but I think it’s worth expanding on the main reason (IMO): hardware can reliably generate an ...
Stephen Kitt's user avatar
10 votes

Why didn't PC games eschew MS-DOS and deal with BIOS directly?

You mean beside the fact that this would make it impossible, or at least quite complex, to install Games on hard disk - which was standard in AT times and later. Likewise for returning to DOS after ...
Raffzahn's user avatar
  • 226k
9 votes

How did 16-bit MS-DOS programs use a large (> 64KB) stack?

The "large" memory model of x86 allowed a program to have multiple code segments and multiple data segment, using far calls to jump across code segments, and far pointers to access data from ...
Raffzahn's user avatar
  • 226k
9 votes

Why is the Compaq FWS2ASPI.SYS driver not recognized as an ASPI driver?

As for example MEM /DEBUG reveals, the Compaq SCSI driver FWS2SCSI.SYS registers itself using the device driver name SCSICPQ$: C:\>MEM /DEBUG Detaillierte Übersicht des konventionellen Speichers: ...
Michael Karcher's user avatar
9 votes

What are the minimum system requirements to run GW-BASIC?

There is no single GW-BASIC. Each OEM could customize portions of it to fit its own custom hardware. For example, I had an Epson computer with a 640x400 all-pixel-addressable video adapter on the ...
Euro Micelli's user avatar
  • 2,805
9 votes

What are the minimum system requirements to run GW-BASIC?

On screen it shows: GW-BASIC 3.10 (C) Copyright Microsoft 1983,1986 61934 Bytes free Looks quite fine to me. Whenever I try to launch the program in one true DOS 6.20, so without the use of any ...
Raffzahn's user avatar
  • 226k
8 votes

How does 2M for DOS (2 MB formatted floppy disks) achieve what it does?

The description of that format does not hint what exactly is used, but there are essentially four ways of stuffing more data into a track, all based on reducing the format overhead of regular sector ...
Raffzahn's user avatar
  • 226k
8 votes
Accepted

What binary format did QuickBasic use for BAS files?

They seemed to be QuickBasic 4.5 files. A proprietary format from QuickBasic that was not only a text file, but included various other concepts like Subs - that were sort of sections into the file. So ...
Dirk Boer's user avatar
  • 311
8 votes

Can DOS make use of more than 640 KB of conventional memory on 80186?

TL;DR: 186 machines are different DOS is not restricted to 640 KiB, but may use the full 1 MiB of real mode address space as RAM. Also, 80186 based PCs (*1)have usually only limited IBM-PC ...
Raffzahn's user avatar
  • 226k
7 votes
Accepted

How to run MOUSSUBS.BAS in QuickBasic? Looking for MIXED.QLB and MOUSE.ASM?

I searched for the filenames and found that MOUSSUBS.BAS and BITS.BAS are from Microsoft QuickBASIC Programmer's Toolbox, a 1988 Microsoft Press book by John Clark Craig. (at least according to https:/...
knol's user avatar
  • 12.5k

Only top scored, non community-wiki answers of a minimum length are eligible