I obtained SVI-105M MSX graphic tablet that had cable cut away (only short torn wires left, no plug), so i had to open it to check how to wire it according to wiki page schematics link. But when i opened this SVI-105M, there is not same schematics at all inside when comparing to wiki page:
ADC chip is adc0833ccn, and there is fewer components in pcb. So I am not sure if this tablet is even working with msx standard or not? As the adc0833ccn datasheet does not show exact same behaviour as the uPD7001 (for example EOC vs SARS signals). And there was 8 signals (8 wires coming inside) connected, two wires are ground and +5v. One wire is connected to ground with jumper wire. There is alternative empty place jumper wire to connect this same signal to ground. But what signal is this then that can be connected to ground? Anyway there is only 5 signals for tablet specific signals, and in wiki page there are six signals SO/SI/EOC/_CS/SENSE/SCK. I figured out that
SO=adc0833ccn DO
SI=adc0833ccn DI
_CS=adc0833ccn _CS,
SCK=adc0833ccn CLK
but now the problem is that only one signal left, so SENSE or EOC ? That one signal that was connected to ground, could that be SENSE or EOC permanently and would that work? Or this tablet anyway needs specific tailor made software to work? I also opened then Pioneer PX-TB7 and verified that it really has that same logic chips as in wiki page.
I will next draw the schematics to kicad.
