Installation guide

370 Installation Guide for Clients
Excluding a Segment of Memory
This section explains how to exclude a segment of memory from use by
the Windows operating system. Specific information about which
segments of memory to exclude for each adapter follows this section.
⇔ To exclude a segment of memory from use by Microsoft Windows
1. Determine the starting address and the size of the segment you want
to exclude, and then use the following sections to determine the
segments you need to exclude for your adapter.
Note that the Windows program excludes paragraphs of memory
(represented in four hexadecimal digits). Certain adapters use memory
addresses (represented in five hexadecimal digits) instead of
paragraph addresses. For the calculations here, memory addresses are
simply paragraph addresses with an extra zero, so the final zeros on
any memory addresses should be dropped.
2. Calculate the last address of the segment you want to exclude using
the starting address and the size of the segment.
3. Convert the size of the segment to hexadecimal so that you can add it
to the starting address (which should be in hexadecimal). For
example, 8K is 0x200 in hexadecimal, and 16K is 0x400 in
hexadecimal. The last address to be excluded is then the starting
address in hexadecimal plus the size of the segment in hexadecimal
minus one. (One is subtracted to get the last address of this segment
rather than the first address of the next segment.)
4. Add a line to the SYSTEM.INI file to exclude the memory from the
starting address of the segment to the last address in the segment.
5. Add a line to the SYSTEM.INI file after the section heading
[386ENH] using the starting address and the last address to be
excluded. If the starting address is 0xD000 and the last address is
0xD1FF, for example, the line in SYSTEM.INI would be:
Note You should exclude this same address range using the x option
for the EMM386 driver in the CONFIG.SYS file.