Switches 2 & 3 seem to set the bus:processor multiplier as follows:
Switch 2 |
Switch 3 |
Multiplier |
Down |
Up |
6x |
Down |
Down |
6.5x |
Up |
Up |
6.5x |
Up |
Down |
7x |
Switch 4 seem to set the processor speed, and is dependent on the bus:processor multipler where up is the slower, and down is the faster of the two. The only way to really look at it is in a table with 2, 3, & 4 as follows:
Switch 2 |
Switch 3 |
Switch 4 |
Multiplier |
Bus (MHz) |
Processor (MHz) |
Down |
Up |
Up |
6x |
50 |
300 |
Down |
Up |
Down |
6x |
Unknown |
Fails to boot |
Down |
Down |
Up |
6.5x |
46.5 |
302 |
Down |
Down |
Down |
6.5x |
Unknown |
Fails to boot |
Up |
Up |
Up |
6.5x |
46.5 |
302 |
Up |
Up |
Down |
6.5x |
Unknown |
Fails to boot |
Up |
Down |
Up |
7x |
43 |
301 |
Up |
Down |
Down |
7x |
43.7 |
306 |
It is unclear what Switch 1 does, but it does not seem to make a difference.
We need to confirm the 306MHz settings, and we're going to try to figure out some of the other bus/processor settings.