Command: rdisk

  RDISK is a DOS RAM-disk driver like tdsk (Turbodisk).

Syntax:

  rdisk [/Sn] [/:L]

Options:

  /Sn  Specifies a desired RAM-disk size in megabytes of XMS memory.
       Values may be any number from 2 to 2047. /S1024 or more
       creates a 1- to 2-GIGABYTE RAM-disk! If /S is omitted or
       invalid, a 25-MB RAM-disk is created by default. For old
       V2.0 XMS managers (ROM-DOS etc.) only /S2 through /S60 may
       be used.
  /:L  Specifies the DOS drive letter desired to access RDISK files.
       L may be any available drive letter from A to Z, e.g. /:N
       assigns drive N: to all RDISK files. If the drive letter
       is too high or already in use, RDISK will abort, and users
       may need "LASTDRIVE=" in CONFIG.SYS to set up more drives.
       If RDISK is loaded by CONFIG.SYS, or if /: is omitted, the
       next free drive letter will be used.

Comments:

  RDISK creates a "fast" disk drive using 2 Megabytes to 2 GIGABYTES of
  XMS memory! It loads as a system driver in CONFIG.SYS, or it can load
  later in AUTOEXEC.BAT or by user command.
  DOS can copy critical programs, data files, and other directories which
  need fast access (compiler TEMP files, databases, etc.) to the RAMdisk,
  where they can be read and written at memory speeds! If loaded after
  CONFIG.SYS, RDISK files can be assigned to any free DOS drive letter by
  using its /: switch. RDISK runs with V2.0 or V3.0 XMS managers (60-MB
  maximum with V2.0 XMS). It uses only 656 to 752 bytes of upper-memory
  depending on the system configuration, and it can also load in 640K DOS
  memory. RDISK is a small "load it and forget about it" driver for use
  when resizing or other features are not needed.
  For more information read "README.txt" in drivers.zip.

Examples:

  IN CONFIG.SYS / FDCONFIG.SYS:
    An example CONFIG.SYS file using V3.70+ UMBPCI and XMGR is as follows:
      SHELL=C:\DOS\COMMAND.COM C:\DOS /E:512 /P
      DEVICE=C:\BIN\UMBPCI.SYS
      DEVICE=C:\BIN\XMGR.SYS /W
      DOS=HIGH,UMB
      DEVICE=C:\BIN\JEMM386.EXE I=B000-B7FF X=C800-EFFF NOEMS   ;Optional
      DEVICEHIGH=C:\BIN\UIDE.SYS /S500 /D:CDROM1                ;Or UIDEJR
      DEVICEHIGH=C:\BIN\RDISK.COM /S250                         ;Optional
          ..
          ..  Etc.
          ..
  An example for AUTOEXEC.BAT:
      LH C:\BIN\RDISK.COM /S500 /:Q          [Load RDISK, assign drive Q:]
         ...
         ...
         ...
      MD Q:\DOS                              [Create RAM-disk directories]
      MD Q:\USERPROG
      MD Q:\ ...
      COPY C:DOS\*.* Q:\DOS                  [Copy DOS files to RAM-disk]
      COPY C:\USERPROG\*.* Q:\USERPROG       [Copy programs to RAM-disk]
      COPY C:\...\*.* Q:\...                 [Copy other files, as needed]
         ...
         ...                                 [Optional:  Verify RAM files]
         ...
      PATH Q:\DOS;Q:\USERPROG;Q:\...         [Tell DOS "new directories!"]

See also:

  autoexec.bat
  config.sys
  fdconfig.sys
 (fdxms (XMS))
 (fdxms286 (XMS))
 (himem (XMS))
  himemx (XMS)
  jemmex (EMS)
  lastdrive
  tdsk

  Copyright © 2010 Jack Ellis, updated 2011 by W. Spiegl.

  This file is derived from the FreeDOS Spec Command HOWTO.
  See the file H2Cpying for copying conditions.