Hot answers tagged

70

DOOM itself doesn’t do anything special to benefit from PCI graphics cards. It runs faster with PCI graphics cards (and VLB, AGP, and PCI Express cards) than with ISA graphics cards because the supporting bus is faster, so reads from and writes to video memory take less time. PCI goes to great lengths to preserve backwards compatibility with ISA-based VGA, ...


58

Because it used to be necessary. While a battery-powered real-time clock is standard today, this wasn’t always the case. The very first IBM 5150 did not include an RTC chip; the system clock was maintained by the PIT interrupt running on the CPU, which in particular meant that disabling interrupts halted the system clock. When the computer was turned off, ...


41

Plain DOS executables, in either COM or MZ format, don’t provide this information in their headers (when there is one — COM format doesn’t have a header). The only reliable way to determine whether a program requires a given CPU is to try running it on some less capable system (or emulation, e.g. with PCem which has accurate emulations of different x86 ...


29

(When selecting an answer, use Stephen's - I just put this here because it is too much text for a comment) Most Important: It's a Game of Raw Numbers. We can ignore more complicated stuff and simply go for bandwidth: ISA had at the time a bandwidth around 16 MiB/s (*2) VLB (*1) and PCI offered up to 133 MiB/s bandwidth. A 320 x 200 screen needs 64 kB (...


26

If you’re going for strict historical accuracy, a 1990 PC could have had either MS-DOS/PC-DOS 3.3, MS-DOS/PC-DOS 4.01, or DR DOS 5, along with Windows 3.0. MS-DOS 5 was released in 1991, and DR DOS 6 followed in the same year. An interesting OEM option is Compaq’s 3.31 DOS, which included support for partitions larger than 32MiB, and the first expanded ...


22

As ecm wrote, DOSEMU supports this, using -t or -dumb. This works with the original DOSEMU and DOSEMU2. -dumb runs DOS programs in “dumb” terminal mode, where output goes to DOSEMU’s standard output and can thus be scrolled back in your terminal or redirected. -t uses S-Lang to provide an emulation of a PC text-mode screen inside the terminal, with colours, ...


18

I discovered the answer on my own. Turns out PSVIEW requires GhostScript, PDFTOPS, and LXPIC to be installed on the hard drive in order to run. GhostScript must be placed in 'C:\gs'. PDFTOPS and LXPIC must be in a directory mentioned in the path environment variable set in 'AUTOEXEC.BAT'.


17

There is no easy way. The original DOS "MZ" type executable header do not contain such information about what kind of code it contains or what CPU type it needs. It just contains a binary image that is loaded to memory and information about how to start it in real mode, so there are no separate 16-bit or 32-bit binaries. The binary image may ...


12

Note all your references to changing values are below the stack pointer, actually a free space. You are not expected to care about this area (stack grows towards lower addresses), as this is of no concern to your application. Even if your computer is sitting at a debugger prompt and apparently is inactive, it isn't. It constantly runs through interrupt ...


10

The FreeDOS kernel doesn’t support USB drives on its own. When you boot from a USB drive, the CSM makes it available through the BIOS 13h services, so it appears to DOS as a “standard” drive and everything works fine. When you boot from your SATA drive, the CSM doesn’t set anything up for your USB drive (although in some cases it can be induced to do so) ...


9

There's also ecm's fork of 8086tiny, ecm-pushbx/8086tiny: ecm's repository for 8086tiny: a tiny PC emulator/virtual machine. Unlike dosemu, it runs on an emulated (not virtual) processor so will run on more hosts. keaston/cp437: Emulates an old-style "code page 437" / "IBM-PC" character set terminal on a modern UTF-8 terminal emulator. is ...


9

It is likely that the "start of track" signal, which is generated when the index hole of the floppy disk passes the sensor, is not sent from the drive to the controller. It could be due to a bad contact somewhere, a broken LED in the drive, a piece of debris stuck in the index hole in the floppy, etc. When reading, the signal is ignored, but it is ...


9

It was necessary, because the early hardware did not contain a Real Time Clock (RTC) chip. The first IBM PC model to have an RTC chip as a standard feature and supported by BIOS was the IBM PC/AT, and earlier models could be retrofitted with an add-on RTC ISA card. So the models before AT cannot possibly know the current time automatically after powering the ...


8

Is there some simple method for determining if a DOS binary (.exe or .dll) is 16-bit or 32-bit? For one, DOS doesn't know about 32 bit, it's a strict 16 bit system. Second, .DLL are not DOS executables but Windows libraries. The Linux file command just says "executable". Because all EXE start out as 16 bit programs, marked by the magic number &...


6

(Caveat: The following information is strictly only true for the XT BIOS, not 100% sure about the XT286, but I'd say it is as compatible here as the AT is) Conclusion from above messages: INT 13h timeout (80h) occures whenever the 'Wait for Interrupt' BOIS routine doesn't detect an interrupt within 2 seconds. So I say the FDC doesn't return from whatever ...


6

I'd say it depends: Plain old DOS is not such a complicated operating system that a free alternative like FreeDOS would really cause severe compatibility problems - At least as long as you stay within the lower 640k. FreeDos is the easiest to obtain and doesn't come with in-built licensing implications. Himem and EMS might cause one or the other ...


5

Somewhat obscure but IDA Pro for DOS was using Turbo Vision Later the same TUI got ported to OS/2, Win32 console and Linux terminal and at one point even iPhone! The TVision version is still shipped today for Win32, Linux and macOS together with the default Qt GUI. Updated cross-platform TVision library source code is available for download.


4

I remember running a version of DOS 4.0 on my 1989-era 386sx machine, along with DesqView/386. Shortly thereafter, we installed Windows 3.0 and then MS DOS 5.0... As far as being period correct and useful, that would be a reasonable place to start. Given the expected life of that 386 box, you could go as new as MS DOS 6.22 and WfWG 3.11 and still be within ...


4

BEAST Behavioral Events Acquisition and analysis SysTem by Windward Technology BEAST grew out of a need for computerized event recording in Ethological research in Dr. George Losey's laboratory at the Dept. of Zoology and the Hawai'i Institute of Marine Biology at the University of Hawai'i. As it matured, more and more statistical analysis routines were ...


3

You have to appreciate that the vast bulk of software written in the world never sees the light of day outside of the business that created it. There are millions of programmers worldwide working every day on applications, yet we as the public see a small fraction of those applications. Most of the code is line of business back office work, software used for ...


3

FLTK for DOS - Apps - XFDOS distro: https://sourceforge.net/projects/fltk-dos/files/Applications/Binary%20versions%20of%20FLTK%20applications/ Here you will find mupdf.zip which has been working very well for me over the last hour since I downloaded it. Acrodos is useless except for viewing the pdfs it came with. You will need cwsdpmi.exe in the same ...


3

A long time ago there was an official release of Acroreader for DOS. I assume it would work with FreeDOS, but I don't know. I also don't know where you might find a copy, but if you search it is probably still out there.


2

Looks like Acrobat Reader 3.0 might be the latest version of Acrobat Reader that will work under Windows 3.11, which you can install in a DOS environment. If you have enough disk space, and are willing to replace FreeDOS with an actual MS-DOS 6.22 install, you can try installing Windows 3.x and use that to read PDFs when needed.


2

In late summer 1994 I upgraded my original IBM AT to DOS 6.22. I had the OS on a 20mb drive and games on a 40mb drive. It was using an Intel AboveBoard with 2 mb memory which I had been using since DOS 5. It was using an enhanced 32kb EGA video card. I do not recall having any difficulty with any of the installed games. My first Packard Bell Pentium 75 ...


2

I can't recall the technical specifics after all this time, but I do remember that my ISA SVGA card (Trident 8900-based) would default to 8-bit bus traffic and 8-bit video-BIOS access. Getting both to 16-bit took quite some BIOS, TSR, and boot-time utility twiddling. Games were noticeably faster in fully 16-bit mode! So I doubt many ISA cards were actually ...


2

I don’t remember any major non-Borland software written using Turbo Vision either. I suspect that if there had been, it would have been listed in part 3 of the Turbo Vision FAQ, “Applications written with Turbo Vision”.


1

Standard PC hardware includes a real-time clock powered by a battery I guess this is a valid assumption since IBM PC AT. Older PCs (PC, PCjr, XT) has no RTC by default (due to Wikipedia).


1

The cause of this change is the fact that you are using the 't' command to step through instructions. That command makes use of a CPU interrupt to regain control after the instruction completes. That interrupt stores state on the stack before transferring control to the interrupt handler. The state on the stack is what you are seeing.


1

I've used DOSBox for the exact same purpose, i.e., playing old games. I found it to be much easier to configure for various things (Soundcards, EMM, Ramdisks, etc.) which many games of old needed. Best of all you can run it on current hardware so you won't have to dig up an old vga monitor out of a landfill.


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