The Commodore CBM-II was a series of business-oriented computers released by Commodore Business Machines starting in 1982. The most popular models were the Commodore 610, 620, 710, and 720 (known as B128, B256, B128-80, and B256-80 in North America). These machines featured a MOS Technology 6509 processor capable of addressing up to 1MB of RAM via bank switching, 128KB-256KB RAM, a MOS 6581 SID chip (same as Commodore 64, but overclocked to 2 MHz), and 80-column monochrome text-only display. Unlike the hugely successful Commodore 64, the CBM-II was designed for business use and had severe technical limitations for gaming: no ability to define custom character sets, no color graphics capability, text-only 80x25 display, and limited to character-based pseudo-graphics at 160x50 PETSCII resolution. These constraints made the CBM-II a challenging platform for game developers and resulted in a minimal commercial game library.
by romhoard-research · 2026/02/14
cbm2
commodore
computer
historical