American Megatrends 42 Series, User Manual

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Appendix A
Upgrading to 256 KB Cache Memory
To upgrade to 256 KB cache memory, use 64 KB x 4 static RAM chips. There are ten pieces in this part, available from
American Megatrends (part numbers):
CPU Speed Access Time Part Number
33 MHz 15 ns Motorola® MCM6208-15
40 MHz 12 ns Toshiba TC5546P-12
The Cache Selection Jumper settings are:
Jumper/
Location 64 KB Cache 256 KB Cache
J50 OPEN Short pins 1-2
and pin 3-4
J51 OPEN Short pins 1-2
and pins 3-4
U32 PRESENT ABSENT
Motherboard Speed Selection
The following table shows the jumper settings to select the motherboard speed.
Jumper 33 MHz 40 MHz
J37 OPEN OPEN
J35 Short pins 2-3 Short pins 1-2
U38 Present Present
U38 is occupied by a 22-pin 64 KB x 1 SRAM with a 12 ns access time.