ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÜÜÜÄÄ 150 Pico Boulevard
ÄÄÄÄÄÄÄÄÄÄÄÄÄÜÜÜÜÜÄÄÄ Santa Monica CA 90405
November 9th, 1993
QEMM Patch for version 7.02 dated 11/9/93
This patchfile implements fixes to QEMM version 7.02. This patch
will work ONLY on QEMM version 7.02. The dates on the QEMM386.SYS (in
your QEMM directory) should be 11/9/93. If the date on these files is later
than 11/9/93, you do not need this patch.
This patch should be applied by copying the files which should
accompany this README (PATCH.EXE, 702to703.RTP, README.RTP,
TECHNOTE.RTP, YESNO.COM and 702to703.BAT) into your QEMM
directory, and then typing
After the patch has been successfully applied, you may delete the
following files (if any still exist) from your QEMM directory:
README.702 (this file)
The following enhancements and changes have been made in the QEMM 7.03
The most significant changes relate to Stealth DoubleSpace:
1) Most of the changes to ST-DBL for QEMM 7.03 relate to compatibility
issues with MS-DOS 6.20 and its two new features: AutoMount and
DoubleGuard. MS-DOS 6.2's DoubleSpace is distinctly different from
the 6.0 version; many modifications were required in QEMM/ST-DBL
7.03 to accommodate these changes.
2) Stealth DoubleSpace should now provide greatly improved performance
on many systems.
Stealth DoubleSpace works by mapping DoubleSpace's code out of DOS'
address space, and then mapping DoubleSpace into the page frame when
that code is needed. DoubleSpace may make calls which require the
disk ROM. When Stealth ROM is active, the disk ROM is also mapped
out of DOS' address space most of the time, and is mapped into the
page frame when it's needed. Mapping the disk ROM into the page
frame requires DoubleSpace's code to be mapped out of the page
frame! To cope with this, Stealth DoubleSpace sets up a buffer into
which data being read from or written to the disk can be placed
temporarily while these mapping operations take place. (QEMM386
sets up a similar buffer when its DBF=n parameter is in use, for
other programs such as EMS disk caches that make disk requests from
the page frame.)
Stealth DoubleSpace in QEMM 7.03 improves on previous versions by
providing buffering at a lower level than before, intercepting and
buffering calls to only those block devices and device drivers
(typically hard drives and disk caches) that were in place when
Stealth DoubleSpace loaded. Stealth DoubleSpace also uses more
sophisticated algorithms to determine when buffering is necessary:
it now provides buffering only when the Stealth ROM feature is
active and when QEMM386.SYS has not already established a disk
3) Without any parameters on the ST-DBL.SYS line in CONFIG.SYS, the
buffer in (2) above is 1K. The size of this buffer can be increased
by adding the DB=x parameter, where x is a number representing the
size of the buffer in kilobytes. A larger buffer gives better
performance at the expense of additional conventional memory or High
RAM overhead. You may wish to try DB=4 when you are using Stealth
ROM and you are not using a disk cache. The buffer can be disabled
by using the DB:N parameter.
To set up a 4K buffer for ST-DBL, add DB=4 to the ST-DBL.SYS line in
4) Expanded memory disk caches may require a different ST-DBL
parameter, EXPCACHE, which makes ST-DBL use a slower but more
comprehensive form of buffering. This parameter has a similar syntax
to DB; EXPCACHE=4 would set up a 4K buffer, and EXPCACHE:Y would
enable this feature with a 1K cache. EXPCACHE:N is a valid
parameter, but is not particularly useful since EXPCACHE is disabled
Other enhancements to the QEMM package include the following:
1) Stealth ROM has been improved to provide better support for video
ROMs on many machines, including Toshiba laptops. This enhancement
should eliminate the need for EXCLUDEs in the C000-C7FF range when
using Stealth on such machines.
2) Stealth ROM has also been enhanced to reduce significantly the need
for XST=C000 and/or EXCLUDES in the C000-C7FF region when using
Microsoft Windows in 386 enhanced mode with high-resolution and/or
proprietary graphics drivers.
3) QEMM386 includes improved support for Compaq machines, which may
suppress spurious ROM 101 Errors at boot time on older BIOSes.
4) QEMM386 better supports Virtual DMA Services, and includes fixes for
some conflicts with Adaptec bus-mastering hard drive controllers.
5) QEMM386's DISKBUF feature (invoked by the DB=nn parameter) now
continues to operate when Microsoft Windows is running in 386
enhanced mode. This gives significantly improved support for
bus-mastering hard drive controllers.
6) Changes have been made to QEMM386 and OPTIMIZE to improve detection
of 32K video ROMs that claim inaccurately to be 24K in size. This
will address problems running OPTIMIZE on Dell machines with Tseng
Labs chipsets. Additionally, QEMM and OPTIMIZE now flush the
instruction cache on 486 processors before rebooting, which will
suppress spurious detection of adapter RAM on some machines.
7) QEMM386 and DOS-Up incorporate better support for MS-DOS'
DoubleSpace and for programs that use the Microsoft Real-time
Compression Interface when QEMM is installed on an uncompressed
8) Stealth and DOS-Up incorporate support for diskless or
floppy-disk-only workstations and remote-boot systems. DOSDATA may
now be used on such systems, and the floppy disk ROMs can be
9) DOSDATA has been modified to suppress printer resets as it
reinitializes the operating system.
10) A potential problem with DOS error code translations has been
addressed. The only known symptom of this problem relates to using
WordPerfect on a a Microsoft LAN Manager read-only drive.
11) Manifest has been enhanced to improve reporting the size of video
ROMs, certain video cards, network directory path names, and higher
baud rates on serial ports.
*These files may be copied and distributed freely as long as they are *
*distributed together, in their entirety, and not distributed for profit.*
* Copyright (C) 1993 by Quarterdeck Office Systems *
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