https://github.com/efliks/demoscene-legacy
VGA mode 13h programming in x86 Assembly
https://github.com/efliks/demoscene-legacy
assembler assembly demoscene graphical-effects mode13h ms-dos retroprogramming vga
Last synced: about 2 months ago
JSON representation
VGA mode 13h programming in x86 Assembly
- Host: GitHub
- URL: https://github.com/efliks/demoscene-legacy
- Owner: efliks
- License: gpl-3.0
- Created: 2015-03-28T00:21:54.000Z (about 10 years ago)
- Default Branch: master
- Last Pushed: 2024-08-25T09:14:11.000Z (10 months ago)
- Last Synced: 2024-08-25T14:37:19.872Z (10 months ago)
- Topics: assembler, assembly, demoscene, graphical-effects, mode13h, ms-dos, retroprogramming, vga
- Language: Assembly
- Homepage:
- Size: 2.56 MB
- Stars: 26
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: COPYING
Awesome Lists containing this project
README
# demoscene-legacy
Back in the early 2000s, I was part of a Polish online group of
Assembler enthusiasts called New Age Assembler Group or NAAG
(now defunct). Some of our works made it to the broader demoscene.
For example, in June 2002 we released our only zine that can still
be found [here](http://www.pouet.net/prod.php?which=50666).
Here is a collection of graphical effects written originally for DOS
in x86 Assembly language. Some of these effects were published on
[Demozoo](https://demozoo.org/sceners/70017/), a demoscene site.
The effects are all implemented in 16-bit Assembly and use real mode.
I have some better effects in 32-bit protected mode Assembly in
a [new repository](https://github.com/efliks/megassembly).
This collection also contained effects written in C, but I have made
a [separate repository](https://github.com/efliks/doseffects) for them.
## Build
To compile and run the graphical effects, there are many options. You can use
a retro PC with DOS, a virtual machine running DOS, or a PC emulator such as
DOSBox or PCem.
Secondly, you need some assembler. Back in the days, I used compilers
from Borland. Luckily, they seem to have become abandonware.
For example, here you can download
[Borland Turbo Assembler 5.0](https://winworldpc.com/product/turbo-assembler/5x).
Once you have the assembler installed, open the attached makefile and replace
the paths to TASM and TLINK with your own.
Then, simply run make:
```
c:\legacy > c:\tasm\bin\make.exe -f makefile
```
## Execute
At this point, you should have around 19 COM files.
Press any key to quit. In *asmshade*, you can press [space] to cycle
between different display modes, and [escape] to quit.
If you are using DOSBox, it may be that some effects run too slowly.
It is possible to accelerate them to some degree by repeatedly
pressing [ctrl + shift + f12], which will increase the number of "cycles"
in DOSBox.
On a system with DOSIDLE installed, it may be necessary to
temporarily switch it off. Otherwise, the animation gets stuck after
a few seconds. To switch off DOSIDLE, use:
```
c:\legacy > c:\dosidle2\dosidle.exe -off
```
## System requirements
The code is really ancient 16-bit Assembly, but it makes use of some
32-bit instructions, e.g. to accelerate copying display buffers. It also
relies on the mathematical coprocessor.
The target platform was a Pentium 133 MHz with a VGA/PCI video card. To
measure the performance on slower systems, I configured several virtual PCs
with 86box, and did some benchmarks with *asmshade*. I recommend at least
a Pentium 100 MHz to have acceptable framerate.
All effects use the tiny memory model, but allocate additional segments.
256 kB of free conventional memory should be enough.
## Final notes
The reason for publishing these programs here is solely because I think
they may still have some educational, fun or nostalgy value for some
people.
I am the only developer of the programs. Licensing information can be
found in COPYING.