

 About

 RDiskSX.COM is a patched version of Jack R. Ellis's RDISK ramdisk driver.


 How rdisk.asm is to be patched

 1. XMS function call ah=89h has to be changed to 0C9h
 2. the XMS lock call following the allocation has to be disabled
 3. the XMS unlock call has to be disabled.

 The lock/unlock function pair in RDISK isn't really needed, 
 because RDISK does not use the physical address returned by the lock.

 Patch 1:

;   mov ah,089h     ;Use V3.0 XMS "allocate memory" code.
    mov ah,0C9h     ;Use HimemSX "allocate super-extended memory" code.
I_GetX:
    call I_XMS      ;Request all necessary XMS memory.
    jnz  I_XmsE     ;Error?  Display message and quit!

 Patch 2:

;   mov  ah,00Ch    ;"Lock" our XMS memory.
;   call I_XMS
;   jnz  I_XmsE     ;Error?  Display msg. & quit!

 Patch 3:

    mov ah,00Dh     ;Unlock and "free" our XMS memory.
    push    dx
;   call    I_XMS
    mov ah,00Ah
    pop dx

