Category: debuggers/debugging tools
Flags: callout or callback (usually hooked rather than called)
INT 2F - MDEBUG display driver - GET DRIVER STATUS AX = D000h Return: CF set on error all other registers must be unchanged) CF clear if successful AL = FFh AH = driver semaphor 00h driver is not active 01h driver is active BX = CS of the driver CX = driver version (CH = major, CL = minor, must be >= 013Ch) DL = buffer semaphor 00h driver is not pending 01h driver is pending between functions 02h and 03h DH = show semaphor 00h driver is not pending 01h driver is pending between functions 04h and 05h 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: 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 actual multiplex numbers used) this function MUST be reentrant, as MDEBUG calls it after every popup before any other actions. The handler should not change any registers if the display is in an unsupported mode or in a mode MDEBUG supports itself, e.g. a normal text mode with at least 80x25 characters (i.e. 80x43 or 132x44 (v1.60+)). In this case MDEBUG will not call any of the other functions for this popup session. MDEBUG will not call the other functions if the returned version is less than the actual version of MDEBUG. if the driver is reentrant, DL and DH should be 00h SeeAlso: AX=D001h,AX=D002h,AX=D003h,AX=D004h,AX=D005h