Mylex MAE486, Руководство пользователя, Страница: 14 / 71

Product overview MBE488 features
MBE486 features
The MBE486 system board is a
system board designed for entry-level
stations. The MBE486 provides the following
features:
Microprocessor INTEL 80486 microprocessor.
BUS
architecture
The MBE486 supports the EISA specification.
The MBE486 provides two files of nonvolatile
RAM. A standard RAM in the Dallas
DS1287 part provides standard SETUP informa-
tion found in all ISA-compatible systems. An ad-
ditional RAM is also included in a Dallas
part, which is required for EISA corn-
patibility.
On-board
memory
The MBE486 provides two SIMM memory
banks. Each bank provides four SIMM socket,
which can accommodate standard,
in-line memory modules Possible
memory configurations using combinations of
and DRAM memory
modules include
Shadow RAM
Memory addresses between 640KB (AOOOOH)
and (FFFFFH) are reserved by DOS for
read-only memory (ROM), video RAM, and other
special uses (such as network management and
page frames). The information in this
range can be copied into RAM on the MBE486
using the same addresses. This 32-bit shadow
RAM provides much faster RAM access to the
information normally stored in ROM.
Note that of the total system memory installed,
384KB is reserved for shadow purpose
(both system BIOS and video BIOS), regardles.
of whether this feature is used. The total amount
of memory available to the user (as reported by
Installation and Operation Guide