Using the BUFFERS.COM utility from any version Quarterdeck expanded
memory manager 386 (QEMM386) before 6.0 with MS-DOS version 4.0 or
later will trigger the following error message:
BUFFERS requires DOS version 2 or 3 to run
Support for MS-DOS version 5.0 was added in the 6.0 release of
QEMM386. BUFFERS.COM continues to be incompatible with MS-DOS versions
4.00, 4.01 and 4.01a.
Look-ahead buffers, introduced in MS-DOS 4.0, allow multiple sector
processing when sequential data is read from or written to a disk.
Quarterdeck BUFFERS.COM does not support this format.
BUFFERS.COM, prior to QEMM version 6.0, is designed to allow users
with QEMM and MS-DOS versions earlier than 4.0 to load system buffers
out of conventional memory with the following line in the AUTOEXEC.BAT
file:
This loads the disk buffers into High RAM, also known as Upper Memory
Blocks. Buffers created with BUFFERS.COM are in addition to buffers
allocated via the BUFFERS= statement in CONFIG.SYS.
With the 6.0 release of QEMM, support for MS-DOS 5.0 was added to
BUFFERS.COM and buffers can be loaded high through the AUTOEXEC.BAT in
the manner listed above. However, there is less need to use
BUFFERS.COM with MS-DOS 5.0 as up to 48 disk buffers can be loaded
into the high memory area (HMA) when MS-DOS is loaded high. For
example, the following lines in the CONFIG.SYS file will allocate 20
buffers which load with MS-DOS into the HMA:
device=c:\qemm\qemm386.sys
dos=high
buffers=20
If more than 48 buffers are in specified using BUFFERS=, all of the
buffers allocated by BUFFERS= will be loaded into conventional memory.
Although all versions of BUFFERS.COM continue to be incompatible with
MS-DOS versions 4.0, 4.01, and 4.01a, buffers can be loaded into
expanded memory (when present) by adding /X to the end of the buffers
line in the CONFIG.SYS file. For example, the line below loads 20 disk
buffers into expanded memory:
The product included here is manufactured by vendors independent of
Microsoft; we make no warranty, implied or otherwise, regarding this
product's performance or reliability.
Reference(s):
"Quarterdeck expanded memory manager 386," version 5.0 pages 43-44.
"Quarterdeck expanded memory manager 386," version 6.0 page 67.