C128 A/V Adapter – Audio/Video for Commodore 128

Product Description

Breaking out the factory A/V port of the computer into standard, modern video and audio connectors.

The adapter connects to the A/V port of the Commodore 128 and outputs signals to commonly available cables: composite video via an RCA connector and/or S-Video via a mini-DIN cable. S-Video, by separating the brightness (luma) and color (chroma) signals, provides a significantly sharper image than the standard composite output built into the C128.

Technical Details

The board includes a 330 Ω resistor on the S-Video chroma signal line, which can be bridged with a jumper if needed—this allows the operation to be adjusted to specific hardware revisions. By default, audio is output in mono, but the adapter also supports optional stereo audio—pin 7 of the A/V port can carry an additional audio source (right channel), which is relevant for extensions like FPGA SID or other stereo add-ons for the C128.

Who Is It For

A solution for Commodore 128 owners who want to connect their computer to a newer TV/monitor or video converter via standard RCA/S-Video instead of the factory, non-standard A/V port, while also having the option to output stereo sound with audio extensions.

Project: https://github.com/svenpetersen1965/C128-A-V-Adapter