INT 21 U - DOS 3.1+ internal - SERVER FUNCTION CALL AX = 5D00h DS:DX -> DOS parameter list (see #01686) DPLsee DOS Parameter List contains all register values for a call to INT 21h Return: as appropriate for function being called Notes: does not check AH. Out of range values will crash the system executes using specified computer ID and process ID sharing delay loops skipped a special sharing mode is enabled to handle FCBs opened across network wildcards are enabled for DELETE (AH=41h) and RENAME (AH=56h) under MS-DOS; under DR DOS 3.41, wildcards corrupt the filesystem; and under DR DOS 5.0-6.0, the call returns error code 03h due to improper support for the server function call (refer to BUGS: section below) an extra file attribute parameter is enabled for OPEN (AH=3Dh), DELETE (AH=41h), and RENAME (AH=56h) functions which take filenames require canonical names (as returned by AH=60h); this is apparently to prevent multi-hop file forwarding BUGS: the OS/2 2.0 DOS BootTo start up the computer or operating system. The term "boot" is a contraction of "bootstrap", which in turn comes from the expression "to lift oneself by one's boot straps." The ROM BIOS on IBMInternational Busiuness Machines PCs and compatibles reads in the first sector of the disk, which contains a short (less than 500 bytes) program that reads in a portion of the operating system, which in turn reads in the remainder of the operating system. See also IPL. Session incorrectly maps DOS drive letters, seemingly ignoring HPFS drives DR DOS 5.0-6.0 merely recursively call INT 21 after loading the registers from the DPLsee DOS Parameter List, leading to problems for peer-to-peer networks SeeAlso: AH=3Dh,AH=41h,AH=56h,AH=60h Format of DOS parameter list: Offset Size Description (Table 01686) 00h WORD AX 02h WORD BX 04h WORD CX 06h WORD DX 08h WORD SI 0Ah WORD DI 0Ch WORD DS 0Eh WORD ES 10h WORD reserved (0) 12h WORD computer ID (0 = current system) 14h WORD process ID (PSPsee Program Segment Prefix segment on specified computer) Note: under Windows Enhanced mode, the computer ID is normally the virtual machine ID (see INT 2F/AX=1683h), though this can reportedly be changed by setting UniqueDOSPSP= in SYSTEM.INI