American Megatrends Enterprise-III User Manual page 12

Specifications,
Continued
Processor Speeds
The Enterprise-III operates at either of two speeds: high or low. High speed is set at time of manufacture to
the processor speed (25, 33, 50, or 66 MHz). Low speed (8 MHz) is simulated by adding extra cycles. The
clock speeds can be changed via the <Ctrl> <Alt> <+> and <Ctrl> <Alt> <-> keychords. These keychords
can be changed by the OEM via AMIBCP.
System Memory
The Enterprise-III EISA motherboard supports up to 256 MB of onboard memory via four banks of 16 MB
x 9 SIMMs. 256 KB x 9, 1 MB x 9, and 4 MB x 9 SIMMs can also be used. Each SIMM bank consists of
four SIMM slots, a total of 16 SIMM sockets. The 70 ns SIMMs must support fast page mode.
Cache Memory
The 256 KB secondary (external) cache memory uses a write-through or write-back caching algorithm. Up
to 64 MB of system memory is cached. There are zero wait states for cache memory read and write for
motherboards operating at speeds up to 33 MHz. Burst mode is supported.
In addition, 80486 processors have an 8 KB internal cache memory. All of system memory is cached in the
80486 internal cache memory.
Both internal and external cache memory is enabled by pressing <Ctrl> <Alt> <Shift> <+> and disabled by
pressing <Ctrl> <Alt> <Shift> <->
Enterprise-III EISA VLB Motherboard User's Guide
7