reposted from old NLG site...
RN3 is a juristiction jumper on the I/O board.
If you boot your Wms slot and get a "JUr bAd" error,
the I/O board needs to be modified so the
firmware matches the I.O board's RN3 jumper.
To elaborate, RN3 is the juristiction jumper on the I/O board.
It must match the firmware or the red LEDs will show a "JUr bAd" error.
On Williams 40x and Dotmation games, RN3 must be set, and
it's a 16 pin DIP, where you run the jumpers across the DIP
(like pin 1 to pin 16, or pin 8 to pin 9). For example:
Standard = no RN3 jumpers
NJ = RN3 switch 8 (jumper pin 8 to pin 9)
MO = RN3 switch 7 (jumper pin 7 to pin 10)
Delaware = RN3 switch 6 (jumper pin 6 to pin 11)
Neveda/Las Vegas = RN3 switch 6 (jumper pin 6 to pin 11) and switch 8 (jumper pin 8 to pin 9)
So again if you get the Red LED error abut "JUr", that means
it's a juristiction error, and the above jumpers need to
be set or cut on the I/O board as indicated above.
I find the "Las Vegas" setting to be most universal, and set up
all my I/O boards that way. If i get an JUr error, then i can just
cut the jumper(s). Easier than soldering (adding) jumpers later.
So set it to Las Vegas with the two jumpers. If you get the error,
cut Switch 6 first and reboot. Still getting the error, cut Switch 8
last and reboot. Between that you should have a working game.
Standard RN3 (no jumpers):
NJ RN3 jumpers (sw8):
Las Vegas RN3 jumpers: (sw8 and sw6). Hey nice soldering there Dave! hehehe:
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CPU board Sound Jumper:
JP2 is the 4meg/8meg EPROM jumper.
jump pin 1 & 2 = 4meg
jump pin 2 & 3 = 8meg
This only applies only to the sound EPROMs.