Monday, June 28, 2010

Desktop OS in 64k - GEOS

Over the last weekend I had a sudden attack of nostalgia for the Commodore 64. I have fond memories of the thing, having one for my first computer. I remembered how there was an operating system available for it that was able to show a graphical desktop, with icons and all, a WYSIWIG word processor, even a spreadsheet, in only 64 kilobytes of memory. It was amazingly tightly coded, and such a difference from today's software that needs tens of megabytes to show a pissy icon in a system tray, for instance.

This operating system was GEOS, standing for Graphical Environment Operating System. An excellent article about it is here. I felt like having a bit of a tinker with it, relive some old memories. One problem though was I no longer had a C64 to load it on. However, emulators came to the rescue. For linux, I installed VICE, which is in the ubuntu repositories. To make it work though, you have to download the version from, that contains the ROM files that are not included in the ubuntu version. There are two ways of putting the ROM files in.

First, the way I tried, was to unzip the version 1.22 file from viceteam, and copy the ROM files into the installation directories (in ubuntu, it is /usr/lib/vice/). The ROM files are the ones without file extensions that live in the data directory in the zip file. They are named 'kernal', 'basic', 'chargen', and so on, and are in different subdirectories for different commodore models the program emulates. Once it is installed and the ROM files are in the right spots, you can start the C64 emulator by typing 'x64' at the command prompt. If all goes well, you will see the C64 screen come up in a window.

The second way, which I did not try, is to follow the instructions here for compiling the latest version of VICE.

Once you have the emulator running, you can download a copy of GEOS. Put the *.D64 files in a directory somewhere, and using VICE, choose the File -> Attach a disk image -> Unit #8 menu. Point it to the GEOS64.D64 file, and it should start loading. You can then marvel at the mid-1980's computing experience. It is similar to the first Mac desktop, but was available for a fraction of the price.

There are other productive things you can do with the Commodore 64 emulator, too...

(Originally posted November 20, 2007 on my other blog)

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