Rally-X
Tekster
|
|
|
Position Option
-------- ------
8 7 6 5 4 3 2 1
-------------------------------
off off *1 coin for 1 play
off on 1 coin for 2 plays
on off 2 coins for 1 play
on on Free play
off off off off 3 cars, rank C, bonus @ 60000
off off off on 2 cars, rank B, bonus @ 40000
off off on off 1 cars, rank C, bonus @ 30000
off off on on 3 cars, rank A, bonus @ 60000
off on off off 2 cars, rank C, bonus @ 40000
off on off on 1 cars, rank B, bonus @ 30000
off on on off 3 cars, rank B, bonus @ 60000
off on on on 2 cars, rank A, bonus @ 40000
on off off off 3 cars, rank C, bonus @ 20000
on off off on 2 cars, rank B, bonus @ 15000
on off on off 1 cars, rank C, bonus @ 10000
on off on on *3 cars, rank A, bonus @ 20000
on on off off 2 cars, rank C, bonus @ 15000
on on off on 1 cars, rank B, bonus @ 10000
on on on off 3 cars, rank B, bonus @ 20000
on on on on 2 cars, rank A, bonus @ 15000
off MAINTENANCE USE ONLY
* indicates default setting
'Switch 8 is for maintenance use only and should normally be in OFF
position. This halts the microprocessor. If it is inadvertently
placed in the ON position, a multicoloured pattern appears on the
screen on power up.'
I've no idea what switch 7 does.
The manual also advises:
'Toggle switches are also found at position 4A on the CPU board. These
are for maintenance only and should not be touched.'
Looking at the circuit diagram, we see that:
Switch1: No connection
Switch2: on: pin 21 of ROMS tied to A12 line.
Off: pin 21 of ROMS isolated
Switch3: on: 'A' input of '139 ROM decoder tied to A12 line.
Off: 'A' input of '139 ROM decoder tied high.
Switch4: on: pin 21 of ROMS tied to +5V
Off: pin 21 isolated
My guess is that they select 2716 or 2732 ROMS.
2716: switch 3,4 on, switch 2 off
2732: switch 3,4 off, switch 2 on