Technical Data DOS/NT Systems Calls The following table represents the industry standard DOS calls supported by DOS/NT. This list is for Release 1.02 as issued on September 16, 1993. int 21 Description State Ver Status --------------------------------------------------------------------------- 00h Terminate Program superseded 1.00 supported 01h Read Keyboard with Echo superseded 1.00 supported 02h Display Character superseded 1.00 supported 03h Auxilliary Input superseded 1.00 supported 04h Auxilliary Output superseded 1.00 supported 05h Print Character superseded 1.00 supported 06h Direct Console I/O active 1.00 supported 07h Direct Console Input active 1.00 supported 08h Read Keyboard Without Echo active 1.00 supported 09h Display String superseded 1.00 supported 0ah Buffered Keyboard Input superseded 1.00 supported 0bh Check Keyboard Status active 1.00 supported 0ch Flush Buffer, Read Keyboard active 1.00 supported 0dh Reset Drive active 1.00 supported 0eh Set Default Drive active 1.00 supported 0fh Open File with FCB superseded 1.00 open 10h Close File with FCB superseded 1.00 open 11h Find First File with FCB superseded 1.00 open 12h Find Next File with FCB superseded 1.00 open 13h Delete File with FCB superseded 1.00 open 14h Sequential Read superseded 1.00 open 15h Sequential Write superseded 1.00 open 16h Create File with FCB superseded 1.00 open 17h Rename File with FCB superseded 1.00 open 18h obsolete 19h Get Default Drive active 1.00 supported 1ah Set Disk Transfer Address active 1.00 supported 1bh Get Default Drive Data superseded 2.00 supported 1ch Get Drive Data superseded 2.00 supported 1dh obsolete 1eh obsolete 1fh Get Default DPB active 5.00 open 20h obsolete 21h Random Read superseded 1.00 open 22h Random Write superseded 1.00 open 23h Get File Size superseded 1.00 open 24h Set Random Record Number superseded 1.00 open 25h Set Interrupt Vector active 1.00 supported 26h Create New PSP superseded 1.00 supported 27h Random Block Read superseded 1.00 open 28h Random Block Write superseded 1.00 open 29h Parse Filename active 1.00 supported 2ah Get Date active 1.00 supported 2bh Set Date active 1.00 supported 2ch Get Time active 1.00 supported 2dh Set Time active 1.00 supported 2eh Set/Reset Verify Flag active 1.00 supported 2fh Get DTA active 2.00 supported 30h Get Version Number active 2.00 supported 31h Keep Program active 2.00 supported 32h Get DPB active 5.00 open 3300h Get CTRL+C Check Flag active 2.00 supported 3301h Set CTRL+C Check Flag active 2.00 supported 3305h Get Startup Drive active 2.00 supported 3306h Get MS-DOS Version active 5.00 supported 33ffh Get DOS/NT Release superset supported 34h Get InDOS Flag Address active 2.00 supported 35h Get Interrupt Vector active 2.00 supported 36h Get Disk Free Space active 2.00 supported 37h Get/Set Switchar undocumented 2.00 supported 38h Get/Set Country Information active 2.00 open 39h Create Directory active 2.00 supported 3ah Remove Directory active 2.00 supported 3bh Change Current Directory active 2.00 supported 3ch Create File with Handle active 2.00 supported 3dh Open File with Handle active 2.00 supported 3eh Close File with Handle active 2.00 supported 3fh Read File or Device active 2.00 supported 40h Write File or Device active 2.00 supported 41h Delete File active 2.00 supported 42h Move File Pointer active 2.00 supported 4300h Get File Attributes active 2.00 supported 4301h Set File Attributes active 2.00 supported 44h Ioctl entry active 2.00 supported 45h Duplicate File Handle active 2.00 supported 46h Force Duplicate File Handle active 2.00 supported 47h Get Current Directory active 2.00 supported 48h Allocate Memory active 2.00 supported 49h Free Allocated Memory active 2.00 supported 4ah Set Memory Block Size active 2.00 supported 4b00h Load and Execute Program active 2.00 supported 4b01h Load Program active 2.00 supported 4b03h Load Overlay active 2.00 supported 4b05h Set Execution State active 5.00 open 4ch End Program active 2.00 supported 4dh Get Child-Program Return Value active 2.00 supported 4eh Find First File active 2.00 supported 4fh Find Next File active 2.00 supported 50h Set PSP Address active 2.00 supported 51h Get PSP Address active 2.00 supported 52h Get List of Lists undocumented 2.00 supported 53h undocumented 54h Get Verify State active 2.00 supported 55h undocumented 56h Rename File active 2.00 supported 5700h Get File Date and Time active 2.00 supported 5701h Set File Date and Time active 2.00 supported 5800h Get Allocation Strategy active 3.00 supported 5801h Set Allocation Strategy active 3.00 supported 5802h Get Upper-Memory Link active 5.00 open 5803h Set Upper-Memory Link active 5.00 open 59h Get Extended Error active 3.00 open 5ah Create Temporary File active 3.00 open 5bh Create New File active 3.00 open 5ch Lock/Unlock File active 3.10 open 5d0ah Set Extended Error active 4.00 open 5eh Generic Network Functions #1 active 3.10 open 5fh Generic Network Functions #2 active 3.10 open 60h undocumented 61h obsolete 62h undocumented 63h obsolete 64h undocumented 65h NLS Functions active 3.30 open 66h Code Page Functions active 3.30 open 67h Set Maximum Handle Count active 3.30 open 68h Commit File active 3.30 open 69h undocumented 6ah undocumented 6bh undocumented 6ch Extended Open/Create active 4.00 open Networks Software Systems, Inc. 23 Cornwall Road Freehold, NJ 07728