Date: Mon, 01 Dec 86 12:30:24 CST
From:  CCRJW%UMCVMB.BITNET@WISCVM.WISC.EDU  (Richard Winkel     UMC
  Computing Services)
To:  INFO-IBMPC@USC-ISIC.ARPA
Subject: Program submission

ADDRIVE.BAT:
rem This .BAT file will create ADDRIVE.COM.  ADDRIVE is used with the
rem SUPERDRIVE ramdisk from AST.  Normally, you must open the system
rem unit and reset switches on the motherboard to use SUPERDRIVE.
rem ADDRIVE resets the 'switches' in RAM, so no hardware switching is
rem required.  The initial run of ADDRIVE will cause the system to
rem reboot, so addrive should be the first command in your autoexec.
rem Example: ADDRIVE C:
rem          SUPERDRV C:/M=180
rem
debug addrive.com <addrive.bat
goto end
a 100
MOV   AL,[005C]                ; get first byte of fcb1
OR    AL,AL                    ; was a drive specified?
JZ    010B                     ; no, print msg & exit
CMP   AL,04                    ; is it <= D: ?
JBE   0114                     ; if so, process it
MOV   DX,0136                  ; else print msg & exit
MOV   AH,09                    ; print msg
INT   21
INT   20                       ; exit
DEC   AL                       ; dec drive number
MOV   CL,06                    ; shift it left 6 bits
SHL   AL,CL
XOR   DX,DX                    ; get to the bottom of memory
MOV   DS,DX
MOV   AH,[0410]                ; get equipment flag
AND   AH,C0                    ; isolate relevant bits
CMP   AH,AL                    ; is this drive already defined?
JB    012B                     ; if not, then define it
INT   20                       ; else exit
AND   BYTE PTR [0410],3F       ; reset 'switches'
OR    [0410],AL
INT   19                       ; and reboot

e 136 'You must supply a drive specifier.$'
rcx
60
w
q
:end

[ADDRIVE.BAT has been added to the Info-IBMPC Library. -rag]