SL> ============================================================
SL> Packet: PC-OHIO
SL> Date: 03-01-97 (10:35)
SL> From: SYLVAIN LAUZON
SL>   To: ALL
SL> Subj: UNKNOWN FUNCTION
SL> Conf: (708) 80XXX-F
SL> ------------------------------------------------------------
SL> I found two unknown functions and potentialy dangerous maybe?
These are not unknown functions...  Get a copy of Ralf Brown's
Interrupts list (e.g. INTRxxx.ZIP) and look them up.
The only thing dangerous is if you go around using commands you
don't know.  Kind of like looking down the barrel of a gun and
pulling the trigger to see what happens.
SL> mov al,00h
SL> mov ah,13h
SL> int 2f
SL> This clear up the DOS from the memory. And it should not! All
SL> it says is "Swap 13h and 19h". It doesn't say much. This
SL> function is used to check for a free "hole" i mean from AH=0
SL> to AH=FF
Look it up in a reference manual..  It's a long one.
SL> Another mysterious one is the following.
SL> mov al,00h
SL> mov ah,55h
SL> int 2f
SL> This one returns 0000. I have no idea why. Segment in memory refers to
SL> command.com
Here is an example of what is found in Ralf Brown's list.
================================================================
--------l-2F5500-----------------------------
INT 2F U - DOS 5+ - COMMAND.COM INTERFACE
        AX = 5500h
Return: AX = 0000h if an instance of COMMAND.COM is already running
        DS:SI -> entry point table
Notes:  used to access the shareable portion of COMMAND.COM,
          which may have been moved into the HMA; only the
          primary COMMAND.COM retains this portion
        procedures called from a dispatcher in COMMAND's
          resident portion; most assume that the segment address
          of the resident portion is on the stack and are thus
          not of general use
SeeAlso: AX=5501h
================================================================
SL> Any thoughts?
Get the proper tools before writing code.
SL> ---
Later,
Steve,  in western New York state (USA)
---
 * QMPro 1.53 * steven.read@pcohio.com
--- InterEcho 1.19
---------------