The GSE AVEP2S is an interesting and rare S-Video processor. It has a lot of logic. And a boot sequence - the panel lights are stepped through when you turn it on - wait what, a boot sequence?
Also an 8 bit MCU and ROM. Really? For a colour processor? This becomes more clear when you notice it also, tantalisingly, has a remote port.
At some point I hope to read out the ROM and preserve it. I used to have a programmer though not at the moment : (
I have looked at the TX port (which is direct from the MCU, thus not RS-232 which needs a driver to get the required levels).
The MCU is CMOS and TTL capable, however the ROM is TTL only. So probably it’s TTL level serial. It follows the TTL standard of port idle = HIGH. The RAM is onboard the MCU.
Hooking it up to a scope, there is data transmitting on the TX port when buttons and knobs are activated and turned!
(it was entirely possible that the remote port was not even implemented in ROM, there is no info on this thing I can find)
It’s set up is very much like an 80s audio synthesizer which I have worked on many times.
I am currently in progress of decoding the serial protocol, and hope at some point to translate this into midi commands. Still it’s fun anyway especially with a rare device.
No service manual or user manual or any info is online. If anyone knows anything about it I’d be happy to hear.
The effects are quite nice, fairly standard, the paint mode is good, and it seems to have an audio to paint function which will be interesting to explore. The inputs are non standard 8 pin full size DINs, so I’ve had to make some custom connectors.
Also I have changed the PSU to accept 15vDC instead of 14vAC. Mainly because I have a 15vDC supply and a 12vAC - 12vAC is too low, when you get it past the bridge rectifier it’s around 10vDC. It has a 12v regulator which feeds a five volt regulator. A separate design would have been nicer but it is compact like this.
Later, I will have a go at messing about and adding some extra logic gates and changing them to get different wipes etc, it’s all analog which is really nice.