Major GEOS applications on the Commodore 64 protect themselves from unauthorized duplication by keying themselves to the operating system's serial number. To avoid tampering with this mechanism, the system contains some elaborate traps, which will be discussed in this article.
The PETSCII character encoding that is used on the Commodore 64 (and all other Commodore 8 bit computers) is similar to ASCII, but different: Uppercase and lowercase are swapped! Why is this?
If you have developed applications for the Commodore 64 in the 80s or 90s, chances are you still have your old floppy disk with the original assembly sources. If you have used the VisAss or
F8 AssBlaster assemblers, you can use a new command line tool I wrote to convert the encoded binary files into ASCII, so they can be published or you can continue development using modern tools like cc65.
The Final Cartridge III was one of the major multi-function extension cartridges for the Commodore 64. It contained BASIC extensions, floppy and tape speeders, centronics printer support, screen editor extensions including F-key shortcuts, a monitor, a freezer – and a GEOS-like windowing system called “Desktop”. In all this, the FC3 integrated seamlessly with the look-and-feel of the stock Commodore 64: It did not change anything (same screen colors and banner!), it only extended functionality in consistent ways.
“The Wave” is a Web Browser for GEOS (with the Wheels extension) on C64/C128 machines with a SuperCPU and a RAM extension.
geowrite2rtf is a tool that converts Commodore 64/128 GEOS GeoWrite documents into RTF format. Most formatting will be preserved, but some formatting and graphics will be discarded.
The Commodore 64 ROM has been subject to immense reverse engineering. Many commented disassemblies were published over the decades, scattered over different media such as books, magazines, disks, and later, the internet – and there are even some commentaries that apply to the C64 ROM, but were written with other systems in mind that shared Microsoft’s BASIC interpreter.
On my quest of collecting as many commentaries on the Commodore 64 ROM at pagetable.com/c64rom, we have gathered Lee Davison’s excellent commentary, the German de facto standard by Data Becker, and an adaptation of Bob Sander-Cederlof’s Apple II ROM commentary, all in the same cross-referenced HTML format.
This is the original 1978 source code of Microsoft BASIC for 6502 with all original comments, documentation and easter eggs:
Whenever I need to look up some code in the ROM of the Commodore 64, I have the choice of the commented disassembly by Marko Mäkelä, the one by Ninja/The Dreams, or the one by Lee Davison – or I can just use my paper copy of “Das neue Commodore-64-intern-Buch“, an excellent line-by-line commentary in German.
by Mike Pall, published with permission.
Nobody doubts that the C64 was the greatest selling single computer model of all time, it even made it into the Guinness Book of World Records, but nobody quite knows how many it really was: Most sources say 17 million, others say 22 or even 30 million. With a high degree of confidence, I can now say that Commodore only sold 12.5 million units – how I would know that, you ask, and how do I dare to contradict well-known facts? By analyzing serial numbers!