Category: debuggers/debugging tools
Flags: callout or callback (usually hooked rather than called)
INT 2F - MDEBUG command driver - GET STATUS AX = D100h BX = version of MDEBUG (BH = major, BL = minor) CX = command driver counter ---v1.60+--- DS:SI -> MDEBUG identification table (see #03076) ES = segment of display memory used by MDEBUG DI = size of video mode used by MDEBUG (high byte = lines, low byte = columns) Return: DL = FFh BX = version number of the driver if it is less than the version in BX, else unchanged CX incremented Program: MDEBUG is a shareware memory-resident debugging tool by Bernd Schemmer, including a memory monitor, an interpreter, and a disassembler Range: AH=C0h to AH=FFh, selected by switch or programmatically Notes: called by MDEBUG at start of popup session; if the version number returned in BX is less than 1.52 (1.60 for MDEBUG v1.70), MDEBUG will not call any of the other functions during this popup session MDEBUG can use any two consecutive multiplex numbers between C0h and FFh; the default is D0h for the display driver and D1h for the command driver (call INT 60/AH=00h"MDEBUG" for the multiplex numbers actually used) this function must end with a far call to the old INT 2F handler after changing the registers this function MUST be reentrant command drivers must also declare the following data at the given offsets in the code segment 100h 3 BYTEs JMP-command in .COM-files 103h BYTE NOP-command (90h) 104h 26 BYTEs signature "Kommandotreiber fr MDEBUG" 11Eh 12 BYTEs name of driver, e.g. "MDHISDRV.COM" each driver must have a unique name MDEBUG will pass every key and command to the command driver(s) before checking for a valid internal command SeeAlso: AX=D000h,AX=D101h