AcerAltos 19000 User’s Guide
5-14
5.3.1 Shadow RAM
The system reserves 384 KB of random access memory (RAM) for the shadow
RAM function. This parameter has eight range addresses. When you set these
addresses to Enabled, the system BIOS, video BIOS, and I/O ROM functions run
directly from the shadow RAM for faster operation. When you set them to
Disabled, the functions run normally from ROM.
The address range E0000h - FFFFFh is for shadowing the system BIOS. This item
is always set to Enabled and is not user-configurable. The address range
C0000h - C7FFFh is for shadowing the video BIOS. This item is fixed to Enabled
and is not user-configurable if the Auto Configuration Mode and the Fast Boot
Mode parameters on page 2 of the Basic System Configuration menu are enabled.
Otherwise, you can choose to disable this item..
The remaining address ranges are for I/O ROM functions.
5.3.2 L1 and L2 Cache (CPU Cache)
This parameter enables or disables the first-level and second-level cache
integrated in the Pentium Pro processor. This item is fixed to Enabled and is not
user-configurable if you enabled the Auto configuration Mode and Fast Boot
Mode parameters on page 2 of the Basic System Configuration menu.

Cache Scheme

This parameter sets the cache to Write-through or Write-back modes. Write-
back updates the cache but not the memory when there is a write instruction. It
updates the memory only when there is cache miss or an inconsistency between
the cache and the memory. Write-through updates both the cache and the
memory whenever there is a write instruction. The default setting is Write-back.