Assembler Programs by Borax Man
This is a selection of assembly programs that I have written. There are quite a few that I’ve written which aren’t here, this is just a small subset.
There is something enjoyable and satisfying about
Dos Assembler Programs
Linux Assembler Programs
DOS
These were written from MS-DOS, mostly back in the late 90’s and early 2000s, but a few more recently.
Keyboard Fun!
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This flashes the lights (capslock, numlock and scrolllock) on the keyboard by manipulating data in the BIOS memory area which stores the keyboard status. The source code is for MASM |
CGA Ball
A very basic demo of a bouncing ball for CGA graphics, using the 640x200 monochrome video mode. This will run on any 8086 processor or greater.
This version is the same program, but stripped back to compile to a binary under 200 bytes. Part of the fun of assembler is making your executables as small as possible.
Bumpmap
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A scrolling bumpmap generated procedurally. The demo is slow because it copies from video memory to video memory, it would be faster to keep the image in a buffer in ram and copy that over and over. Perhaps I’ll get to fixing that, it is an easy fix, but the need to improve this isn’t really there. |
Chain
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This is the same program, but modified to make the bumpmap appear more like a ‘chain’ |
XMS Demo
Nothing more than an example of how to use XMS memory.
Adlib
Nothing more than an example of how to produce a note through the OPL3 FM synthesis chip. The code isn’t well exemented though.
Interrupt Demo
A demonstration of interrupt driven program. This creates a custom interrupt handler which is triggered by the PC timer.
COM Demo
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A more recent program of mine, an example of a COM file. This demostrates the use of the PC speaker, taking input and use of screen memory. It just asks for text and displays it multiple times in dazzling colour. Nothing special, but my younger child actually likes playing around with this. The source code is for FASM. |
Star Scroller
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A VGA star scrolling demo. I tried to emulate some depth of field to this. Will run on any 286 with a VGA card. FASM source code. |
Smile Bounce
This is 6502 assembler, a different chipset which is simpler than the x86 architecture, and quite enjoyable to program for, because of its simplicity. Though at times you can wish this CPU had multiple and divide instructions. This program is written specifically for the VIC 20, which was a computer I had for a short period in the early 90s. I still have one now, although it is in need of repair. The VIC 20 only has 5K of RAM, a fairly low graphics resolution as compared to other microcomputers of the 80’s and 90’s and basic sound. Nevertheless, this makes it an endearing machine and I had always wanted to write machine code for the VIC 20 or Commodore 64 back in the day but had neither the knowledge or means to do so. Now it is easy so I wrote this demo to explore the capabilities of the VIC, its CPU interrupt system, changing the screen size, something I had no idea could be done until I started this project, sound and graphics.
This just bounces a ball, which you can move with the keyboard, while playing a tune and scrolling a message. It takes up most of the free RAM and demonstrates also self modfying code. It is probably a good example if you want to learn more about the VIC 20.
Compile with ca65.
This is a .PRG file you can load straight into your emulator. If using Vice, you can autostart at the command line with
xvic -autostartprgmode 1 smilebounce.prg
Linux
wadinfo
Simple program in x86 which lists the directory contents of a wadfile (the data file for Doom engine games)
Compile with gas assembler.
PC Speak 2
Simple demonstration of using the PC Speaker under Linux.
FASM source.
LPT Console
This program allows you to output single bytes to the parallel port.
GAS source.