14-06-2021, 02:34 PM
Not sure if I've posted this before on GVR. This is the handwired prototype PAL coder I designed for G2 Systems in 1986/7. It was my first full design project when I went self-employed. This one still works. It does PAL coding for the COW (Computer Originated World) at the Dulwich Museum. Not very good off-screen picture of COW output (via coder) attached.
When I dug it out a few years ago after many years in storage I found one duff CMOS chip and one wire dropped off. Adjustments were more or less spot on. I did a minor mod to provide a mixed sync output to lock the COW.
Construction is on plain peforated board with components mostly mounted on pins. Heavy 0V bus around edge. It runs on +/-8V to +/-12V. Originally +/-9V as that was what we used at Michael Cox Electronics in the early 1980s and I had a few old PSUs around. It has a built-in SPG and will free-run with reasonable accuracy. It will genlock to another PAL signal, ideally colour black. It was originally designed to work with a modified BBC Microcomputer that could genlock to to a video reference. That was done by my former Cox colleague Graham Rendell under the banner of his company, Abbey Audio. It's just possible I still have details and schematic for that kit.
When I dug it out a few years ago after many years in storage I found one duff CMOS chip and one wire dropped off. Adjustments were more or less spot on. I did a minor mod to provide a mixed sync output to lock the COW.
Construction is on plain peforated board with components mostly mounted on pins. Heavy 0V bus around edge. It runs on +/-8V to +/-12V. Originally +/-9V as that was what we used at Michael Cox Electronics in the early 1980s and I had a few old PSUs around. It has a built-in SPG and will free-run with reasonable accuracy. It will genlock to another PAL signal, ideally colour black. It was originally designed to work with a modified BBC Microcomputer that could genlock to to a video reference. That was done by my former Cox colleague Graham Rendell under the banner of his company, Abbey Audio. It's just possible I still have details and schematic for that kit.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv