Category: DOS kernel
INT 21 - European MS-DOS 4.0 - "AEXEC" - EXECUTE PROGRAM IN BACKGROUND AH = 80h CX = mode 0000h place child in zombie mode on exit to preserve exit code 0001h discard child process and exit code on termination DS:DX -> ASCIZ full program name ES:BX -> parameter block (as for AX=4B00h) Return: CF clear if successful AX = Command Subgroup ID (CSID) CF set on error AX = error code (see #01680 at AH=59h/BX=0000h) Program: European MS-DOS 4.0 was written for Siemens in Germany and then used by several other European OEMs; its release falls between mainstream versions 3.2 and 3.3 Desc: asynchronously execute a program, creating a new process for it Notes: this function is called by the DETACH command there is a system-wide limit of 32 processes the CSID is used to identify all processes that have been spawned by a given process, whether directly or indirectly programs to be run in the background must use the new executable format (see #01596 at AH=4Bh) background processes may only perform asynchronous (background) EXECs, either this function or AX=4B04h background processes may execute INT 11, INT 12, INT 21, INT 2A, and INT 2F at any time; they may execute INT 10 and INT 16 only while they have opened a popup screen via INT 2F/AX=1401h; no other interrupts may be executed from the background background processes may not use drive B: or overlay their code segments see AX=8700h for an installation check the "NE" new executable format made its first appearance in European MS-DOS 4.0 SeeAlso: AH=4Bh,AH=87h,INT 2F/AX=1400h"POPUP"