-> I found two unknown functions and potentialy dangerous maybe?
->
-> mov al,00h
-> mov ah,13h
-> int 2f
->
-> This clear up the DOS from the memory. And it should not! All it says
-> is "Swap 13h and 19h". It doesn't say much. This function is used to
-> check for a free "hole" i mean from AH=0 to AH=FF
My book on PC Interrupts (Ralf Brown & Jim Kyle) says int 2Fh function
13h is an undocumented call to DOS 3.2+ to change the disk interrupt
handler, with DS:DX pointing to the new handler for INT 13h, and ES:BX
pointing to the address to restore on system halt.  It also says that it
returns the previous values of those (from previous invocations, or
IO.SYS setting it)
->
-> Another mysterious one is the following.
->
-> mov al,00h
-> mov ah,55h
-> int 2f
->
-> This one returns 0000. I have no idea why. Segment in memory refers
-> to command.com
This one's an undocumented Dos 5+ call to get the command.com interface,
since most of it may have been moved to a HMA.  ax returning 0000 means
there is already an instance of COMMAND.COM running.
((Cloud))
B$SN$
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