home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Shareware Supreme Volume 6 #1
/
swsii.zip
/
swsii
/
198
/
DOS6ALL.ZIP
/
Q96522
< prev
next >
Wrap
Text File
|
1993-06-05
|
2KB
|
43 lines
ARTICLE-ID:Q96522
TITLE :Regions Scanned by the EMM386.EXE HIGHSCAN Switch
--------------------------------------------------------------------
The information in this article applies to:
- Microsoft MS-DOS operating system version 6.0
--------------------------------------------------------------------
Summary:
The HIGHSCAN switch included in EMM386.EXE version 4.45 allows
EMM386.EXE to map expanded memory pages or upper memory blocks (UMBs)
over portions of the upper memory area (UMA) used by system read-only
memory (ROM).
Choosing "Yes" in response to the MemMaker prompt "Scan the upper
memory area aggressively?" causes MemMaker to add HIGHSCAN to the
EMM386.EXE device= line.
More Information:
If you use the HIGHSCAN switch on the DEVICE=C:\DOS\EMM386.EXE line in
the CONFIG.SYS file, EMM386.EXE examines the system ROM area starting
at memory location F000:0000. If EMM386.EXE determines that ROM is
duplicated between F000h-F7FFh and F800h-FFFFh, EMM386.EXE uses the
F000h-F7FFh region for expanded memory page mapping or UMB memory.
(This adds up to 32 kilobytes to the UMA.
On Micro Channel (MCA) systems with ROM BASIC (for example, IBM PS/2
systems), the HIGHSCAN switch allows EMM386.EXE to map expanded memory
or UMB memory over the ROM BASIC code in the system ROM. Typically
this is the region from F600 to FDFF.
Note: On some systems, EMM386.EXE uses the ROM area and the system
does not operate correctly. The symptoms of this condition vary. For
example, the system may stop responding (hang) or appear to operate
normally until you use a floppy disk drive. Because of these potential
problems, HIGHSCAN is not used by default.
Additional reference words: 6.00 parameter