Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

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Using RAMDDRIVE.SYS
The RAMDRIVE.SYS device driver allows you to use a portion of your
computer's memory as an additional hard disk. This disk is referred to
as a RAM disk or virtual disk, and it is much faster than a physical hard
disk. You can place a RAM disk in conventional, extended, or expanded
memory. On most machines, RAMDRIVE.SYS runs fastest on expanded memory.
To use RAMDRIVE.SYS with extended memory, you must have an 80286 or later
processor, or an AT&T 6300 PLUS.
 
The system reads and writes to the RAM disk almost as fast as to conventional
memory. If you set the TMP environment variable to a directory on a RAM disk,
a number of programming tools (notably LINK and ISAM) will use the RAM disk
to hold temporary files, thus speeding up operations.
 
To install RAMDRIVE.SYS, include the following command line in
your CONFIG.SYS file:
 
    device=RAMDRIVE.SYS [disksize][sectorsize][entries][{/A | /E | /U}]
 
The RAMDRIVE.SYS device driver syntax contains the following options:
 
Option              Function
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disksize            Specifies the disk size in kilobytes. The default size
                    is 64K, the minimum size is 16K, the maximum size is
                    4096K.
 
sectorsize          Specifies the sector size in bytes. The default size
                    is 512 bytes. The values 128, 256, 512, and 1024 bytes
                    are allowed.
 
entries             Specifies the number of root directory entries.
                    The default value is 64; the minimum is 2; the maximum
                    is 1024.
 
                    RAMDRIVE.SYS adjusts the value of entries to the nearest
                    sector boundary. For example, if you specify a value
                    of 25 when the sector size is 512 bytes, the 25 will
                    be rounded up to 32, which is the next multiple of 16.
 
/A                  Lets you use an installed expanded memory board that
                    meets the Lotus/Intel/Microsoft 4.0 Expanded Memory
                    Specification for a RAM drive. The /A, /E, and /U
                    options cannot be used together.
 
/E                  Lets you use installed extended memory above 1 Mb as a
                    RAM disk. The /A, /E, and /U options cannot be used
                    together.
 
/U                  Specifies that some or all of the 384K of extra memory
                    on the AT&T 6300 PLUS motherboard is to be used as
                    an extra RAM drive. For use on an AT&T 6300 PLUS only.
                    The /A, /E, and /U options cannot be used together.
 
Note     When you reset or turn off you computer's power,
         the information stored in RAM disks is lost.
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  See Also    ◄Using HIMEM.SYS►
              ◄Using SMARTDRV.SYS►