DRVSPACE.SYS--Notes

DRVSPACE.SYS does not provide access to compressed drives

The DRVSPACE.SYS device driver does not provide access to compressed drives;
it simply moves DRVSPACE.BIN to its final location in memory. (DRVSPACE.BIN
is the part of MS-DOS that provides access to compressed drives; it loads
with other operating system functions, before MS-DOS carries out the
commands in your CONFIG.SYS file.)

If your compressed drive's host drive requires a device driver

A few disk drives require an installable device driver. If such a drive
contains compressed volume files (either you compressed that drive, or you
created new compressed drives on that drive), the command for the
DRVSPACE.SYS device driver must appear in the CONFIG.SYS file after the
command for your drive's device driver. Otherwise, DriveSpace will not mount
any compressed volume files located on that drive when your computer
starts.

Avoiding conflicts with programs that require access to the top of
conventional memory

When you start your computer, MS-DOS loads DRVSPACE.BIN at the top of
conventional memory; after processing the CONFIG.SYS file, MS-DOS moves
DRVSPACE.BIN to the bottom of conventional memory.

However, a few programs that are loaded from the CONFIG.SYS file require
access to the top of conventional memory and do not work properly if
DRVSPACE.BIN is located there. To avoid such conflicts, DriveSpace Setup
adds a command for DRVSPACE.SYS before any command that starts a program
that is known to require this area of memory. The DRVSPACE.SYS device driver
moves DRVSPACE.BIN from the top of conventional memory to another area of
memory (either to the bottom of conventional memory or to upper memory).

Depending on your configuration, your CONFIG.SYS file might contain more
than one command for DRVSPACE.SYS. This will not cause any problems.

Moving part of DRVSPACE.BIN to the high memory area

By default, if your CONFIG.SYS file contains a DOS=HIGH command,
DRVSPACE.SYS moves the compression server, a portion of DRVSPACE.BIN, to the
HMA. To move a portion of DRVSPACE.BIN to the HMA, you must have an 80286 or
higher computer with extended memory, and must be running HIMEM or another
extended-memory manager.

Moving DRVSPACE.BIN to upper memory

When loaded with a DEVICEHIGH command, the DRVSPACE.SYS device driver moves
DRVSPACE.BIN from conventional to upper memory. If there is no upper memory
block large enough to accommodate DRVSPACE.BIN, it is instead moved to the
bottom of conventional memory.

To use the upper memory area, you must have an 80386 or 80486 computer with
extended memory.

Using BUFFERS with DriveSpace

If you are using DriveSpace and SMARTDrive, and MS-DOS is loaded into the
HMA, set BUFFERS=10. This ensures that there will be enough room in the HMA
for MS-DOS, DriveSpace, and all your buffers. (If BUFFERS is set to a value
higher than 10, there might not be enough room in the HMA for all your
buffers, and MS-DOS will place all the buffers into conventional memory.) If
you're using SMARTDrive, specifying more than 10 buffers will not speed up
your system much, but will use additional memory.