MS DOS Command: DRVSPACE.SYS

Reference from Microsoft MS-DOS cmd help

Description

Determines the final memory location of DRVSPACE.BIN, the part of MS-DOS that provides access to your compressed drives.

When you start your computer, MS-DOS loads DRVSPACE.BIN along with other operating system functions, before carrying out the commands in your CONFIG.SYS and AUTOEXEC.BAT files. DRVSPACE.BIN initially loads in conventional memory because it loads before device drivers that provide access to upper memory.

When you run DriveSpace Setup, it adds a command for DRVSPACE.SYS to your CONFIG.SYS file.

Syntax

DEVICE = [drive:][path]DRVSPACE.SYS /MOVE [/NOHMA] DEVICEHIGH = [drive:][path]DRVSPACE.SYS /MOVE [/NOHMA]

Parameters

[drive:][path]

Specifies the location of the DRVSPACE.SYS file.

Switches

/MOVE

Moves DRVSPACE.BIN to its final location in memory. Initially, DRVSPACE.BIN loads at the top of conventional memory. After MS-DOS finishes carrying out the commands in the CONFIG.SYS file, it moves DRVSPACE.BIN to the bottom of conventional memory. When DRVSPACE.SYS is loaded by using the DEVICE command, it moves DRVSPACE.BIN from the top of conventional memory to the bottom. This can be useful for avoiding conflicts with programs that are loaded from the CONFIG.SYS file and require access to the top of conventional memory. When DRVSPACE.SYS is loaded by using the DEVICEHIGH command, DRVSPACE.BIN moves to upper memory, if available. Moving DRVSPACE.BIN to upper memory makes more conventional memory available.

/NOHMA

Prevents DRVSPACE.SYS from moving a portion of DRVSPACE.BIN to the high memory area (HMA). If MS-DOS is loaded into the HMA, DRVSPACE.SYS moves a portion of DRVSPACE.BIN to the HMA (if there is enough room in the HMA). Use this switch if you do not want DRVSPACE.BIN to use the HMA. (It is not necessary to use this switch if you upgraded to MS-DOS 6.22 from MS-DOS 6.0.)

Remarks

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.

Examples

To move a portion of DRVSPACE.BIN to the HMA and move the rest to the bottom of conventional memory, you must have an 80286 or higher computer, and your CONFIG.SYS file must contain a DOS=HIGH command and a DEVICE command for HIMEM or another extended-memory manager. Load DRVSPACE.SYS by using the following command:

device=drvspace.sys /move

To move a portion of DRVSPACE.BIN to the HMA and the rest to the upper memory area (if available), you must have an 80386 or higher computer with extended memory. Ensure that your CONFIG.SYS file contains a DEVICE command for DRVSPACE.SYS, and then run MemMaker.

To move all of DRVSPACE.BIN to the bottom of conventional memory, and to prevent DRVSPACE.BIN from using the HMA or upper memory, load DRVSPACE.SYS by using the following command:

device=drvspace.sys /move /nohma

To move all of DRVSPACE.BIN to upper memory (if available), and to prevent DRVSPACE.BIN from using the HMA, load DRVSPACE.SYS by using the following command:

devicehigh=drvspace.sys /move /nohma