Saturn jumpers ... ?

[Tiido Priimägi]

There's quite a few of jumpers on (my) Saturn board... 8 of them are well documented but what about others ?

I've marked the jumpers I could find on my board (also, what revision board I have ?).
JP1 is probably PAL/NTSC select for CXA1645...

[Tiido Priimägi]

...And top scan of the board, This is from an European oval button machine.

[l_oliveira]

JP1 also changes the VDP refresh to 50hz.

There's a jumper close to the clock synthesizer chip (a small Hitachi QFP chip which on that mobo is probably re-labeled as SEGA 315xxxx part number) to select 14mhz(NTSC)/17mhz(PAL) clock, too.

[Tiido Priimägi]

thank you for the info.

[l_oliveira]

By looking at your pictures it seems like JP4 and JP5 do change the frequency from 14mhz(3.5759545x4) to 17mhz(4.433619x4)
And yours is set to 17mhz.