Commodore's 8-bit computers initially lacked an operating system in the strict sense. These computers interacted through commands embedded in their BASIC programming language, and startup and initial use of various system parts were done using these commands.

Commodore BASIC was initially known as PET BASIC or CBM Basic, a branch of Microsoft BASIC used in Commodore's 8-bit computers from 1977 to 1985. This BASIC, designed around the 6502 processor core, had many similarities with other 6502-based BASIC languages such as AppleSoft BASIC.

As previously mentioned, Commodore purchased a "royalty-free" license from Microsoft in 1977, after the clever Jack Tramiel rejected Bill Gates's offer of $3 per unit and paid $25,000 for a permanent license.

Versions of Commodore BASIC

BASIC version 4 used in the Commodore PET is the same BASIC 2 used in the VIC-20 and Commodore 64. BASIC 3.5 added graphics and sound support in the Commodore 16 and Plus/4. BASIC 7 was dedicated to the Commodore 128. The last Commodore BASIC, version 10, was part of the unreleased Commodore 65.

The Commodore 65 is an improved version of the Commodore 64 with advanced features close to the Amiga.

The Home Computer Magazine — Commodore's internal publication — covered the Commodore and Amiga computer families.

GEOS; A Graphical OS for 64 Kilobytes

GEOS stands for Graphical Environment Operating System — a GUI operating system for the Commodore 64, Commodore 128, Apple II, and Commodore Plus/4. It was released in 1986 by Berkeley Softworks.

Years before Microsoft Windows, GEOS ran on 64 kilobytes of memory:

The Story Behind GEOS

Brian Dougherty founded Imagic and later formed BSW. BSW worked on an airline product called Sky Tray — a battery-powered computer for the tray behind airplane seats. When airline deregulation happened, the Sky Tray program was canceled. Then Mr. Dougherty realized he had an unused operating system for 6502-based computers — and GEOS was born.

GEOS was introduced for the Commodore 64 in March 1986. In 1987, it was released for the Commodore 128, and in 1988 for the Apple II.

The Evolution of GEOS

GEOS 1.0 shipped with "deskTop," "geoWrite," "geoPaint," and desktop accessories. GEOS 2.0 was released in 1988 with color graphics and more features.

In 1993, GEOS 2.5 was released in Germany. In 1998, Maurice Randall released the "Wheels" upgrade.

With the SuperCPU accelerator, the Commodore 64 or 128 can run at 20 MHz. Read about hardware maintenance in the exclusive AmigaStore article.

But with the powerful Amiga, does an opportunity remain to experience GEOS? In the next section of the book, we will step into the wonderful and colorful world of the Amiga.