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Old Retro-Bits

This page, when I get a chance to look through my old archives, will host all of my old ā€œCā€ and Assembly language source files for my original 8- and 16-bit games and software. My commercial career began in 1988 when I was 18 years old and started United Coders, a game studio focusing on the Commodore C64 and AMIGA series of home computers.

Even before then, I had been programming on the Amstrad CPC464 in 1985-1986, mostly for fun and to learn Z80 Assembly programming. On the C64 I wrote mostly games – in pure 6502 assembly, and on the Commodore AMIGA, I focused my efforts on applications and utility software using a real Assembler package with mnemonics. My first commercial game, a vertical shooter for the C64 called Criminal Insane, released on cassette and was coded in opcodes using nothing but a machine language monitor.

My biggest accomplishment on the Commodore AMIGA was a complete rewrite of the Intuition (GUI) kernel. In pure 68000 Assembly, I re-coded and re-created a custom KickStarter v1.3 library that simulated features of the newer AMIGA OS 2.x and AMIGA OS 3.x. It basically meant that anyone could write custom application software on the original OS v1.x having the look and feel of the most recent OS available. The project took two years of programming to complete and my Devpac 3 Assembly files exceeded one million lines of code, including comments and references files. I still have the original source code lying around, and will share those once I get an opportunity to extract the most recent version. When the project was complete I created a series of utility applications that demoed how to use the library in a commercial environment. Here are some sample images.

You may also enjoy some old magazine articles I wrote in the early 1980s and 1990s when I was an aspiring writer in a time and era when print magazines was all that existed. I wrote hundreds of articles as a freelancer and only a few have been scanned. Note that all articles are in Danish.

AMIGA Viruses Explained

Boston Computer Museum

World Of Commodore

ASSEMPRO Assembler

More recently, in August of 2001, I was the co-founder and European Editor-In-Chief of Insert Coin, an exclusive trade-only publication sponsored entirely by ads with a print circulation of 10.000 copies. Insert Coin was distributed to industry peers, analysts, insiders and members of the press.

Hans Frederik Olsen | Celebrating 30 Years In Games | 1987 - 2020