In 2021, Neil Cohen sent a few TS 2068 computers in various states of repair. One computer had a home-brew RGB converter built inside and around the composite video output jack. Here’s what it looked like when I opened the case.
I extracted the board, disconnected it and traced the circuit as best I could. Here are some more photos and the schematic.
As you can see, there are three integrated circuits and a few discrete parts.
In mid-2022, Tim Swenson scanned issues of CATS, the newsletter of the Capital Area Timex Sinclair User Group.
Among those issues was an article about several club members who took it upon themselves to design and build their own RGB converter. Herb Schaaf wrote up the results, which appeared in two separate issues.
The first article, “Retrace Lines: 2068 and RGB Monitor,” described their effort and the circuit.
The actual schematics were published a few months later in “The Art Gallery.“
As you might have guessed, the circuit those user group members designed is the same one built into the TS2068 I received from Neil Cohen.
