What Is the Commodore VIC-20 Video Chip Model Number?

This article identifies the specific video chip model numbers used in the Commodore VIC-20 home computer. It distinguishes between the regional variants of the hardware and explains the significance of the Video Interface Chip in the machine’s architecture and naming convention.

The specific model number of the video chip inside the Commodore VIC-20 is the MOS Technology 6560 for NTSC systems and the 6561 for PAL systems. This custom integrated circuit was responsible for generating the video signal, managing memory access for the display, and handling the system’s graphics capabilities. The computer itself was named the VIC-20 specifically because of this Video Interface Chip, marking it as the first affordable color computer to feature custom graphics hardware designed in-house.

While the core architecture remained consistent across regions, the distinction between the 6560 and 6561 was necessary to accommodate the different refresh rates and color encoding methods used in North America versus Europe and other PAL regions. The NTSC version, the 6560, operated at 60Hz, while the PAL version, the 6561, operated at 50Hz. Despite these differences, both chips provided the characteristic text and block graphics that defined the user experience on the VIC-20.