00h (0)                 Terminate Program 
 01h (1)                 Read Keyboard Character and Echo 
 02h (2)                 Character Output 
 03h (3)                 Auxiliary Character Input 
 04h (4)                 Auxiliary Character Output 
 05h (5)                 Printer Character Output 
 06h (6)                 Direct Console Character I/O 
 07h (7)                 Direct Console Character Input without Echo 
 08h (8)                 Console Character Input without Echo 
 09h (9)                 Print String 
 0Ah (10)                Buffered Input 
 0Bh (11)                Check Standard Input Status 
 0Ch (12)                Clear Input Buffer, then Invoke Function 
 0Dh (13)                Disk Reset 
 0Eh (14)                Select Default Drive 
 0Fh (15)                Open File, Using FCBs 
 10h (16)                Close File, Using FCBs 
 11h (17)                Search for First Matching File, Using FCBs 
 12h (18)                Search for Next Matching File, Using FCBs 
 13h (19)                Delete File, Using FCBs 
 14h (20)                Sequential Read, Using FCBs 
 15h (21)                Sequential Write, Using FCBs 
 16h (22)                Create File, using FCBs 
 17h (23)                Rename File, using FCBs 
 18h (24)                Reserved 
 19h (25)                Get Current Disk 
 1Ah (26)                Set Disk Transfer Address (DTA) 
 1Bh (27)                Get FAT Information for Current Drive 
 1Ch (27)                Get FAT Information for Specified Drive 
 1Dh (29)                Reserved 
 1Eh (30)                Reserved 
 1Fh (31)                Reserved 
 20h (32)                Reserved 
 21h (33)                Random Read, Using FCBs 
 22h (34)                Random Write, Using FCBs 
 23h (35)                Get File Size, Using FCBs 
 24h (36)                Set Random-Record Field, Using FCBs 
 25h (37)                Set Interrupt Vector 
 26h (38)                Create Program Segment 
 27h (39)                Random Block Read, Using FCBs 
 28h (40)                Random Block Write, Using FCBs 
 29h (41)                Parse Filename 
 2Ah (42)                Get System Date 
 2Bh (43)                Set System Date 
 2Ch (44)                Get System Time 
 2Dh (45)                Set System Time 
 2Eh (46)                Set or Reset VERIFY Switch 
 2Fh (47)                Get Disk Transfer Address (DTA) 
 30h (48)                Get DOS Version Number 
 31h (49)                Terminate and Stay Resident 
 32h (50)                Reserved 
 33h (51)                Get or Set Ctrl-Break Status 
 34h (52)                Reserved 
 35h (53)                Get Interrupt Vector 
 36h (54)                Get Disk Free Space 
 37h (55)                Reserved 
 38h (56)                Get or Set Country-Dependent Information 
 39h (57)                Create Directory (MKDIR) 
 3Ah (58)                Remove Directory (RMDIR) 
 3Bh (59)                Change Directory (CHDIR) 
 3Ch (60)                Create a File (CREAT) 
 3Dh (61)                Open a File 
 3Eh (62)                Close a File Handle 
 3Fh (63)                Read from File or Device, Using a Handle 
 40h (64)                Write to File or Device, Using a Handle 
 41h (65)                Delete File (UNLINK) 
 42h (66)                Move File Pointer (LSEEK) 
 43h (67)                Get or Set File Attributes (CHMOD) 
 44h (68)                I/O Control for Devices (IOCTL)             Overview 
 4400h (68-0)            IOCTL: Get Device Information 
 4401h (68-1)            IOCTL: Set Device Information 
 4402h (68-2)            IOCTL: Read from Character Device 
 4403h (68-3)            IOCTL: Write to Character Device 
 4404h (68-4)            IOCTL: Read from Block Device 
 4405h (68-5)            IOCTL: Write to Block Device 
 4406h (68-6)            IOCTL: Get Input Status 
 4407h (68-7)            IOCTL: Get Output Status 
 4408h (68-8)            IOCTL: Is Device Removable?                ò DOS 3.0 
 4409h (68-9)            IOCTL: Is Logical Device Remote?           ò DOS 3.1 
 440Ah (68-10)           IOCTL: Is Handle Remote?                   ò DOS 3.1 
 440Bh (68-11)           IOCTL: Change Sharing Retry Count          ò DOS 3.0 
 440Dh (68-13)           IOCTL: Generic IOCTL Request               ò DOS 3.2 
 440Eh (68-14)           IOCTL: Get Logical Drive                   ò DOS 3.2 
 440Fh (68-15)           IOCTL: Set Logical Drive                   ò DOS 3.2 
 45h (69)                Duplicate a File Handle (DUP) 
 46h (70)                Force Handle Duplication (FORCDUP) 
 47h (71)                Get Current Directory 
 48h (72)                Allocate Memory 
 49h (73)                Free Allocated Memory 
 4Ah (74)                Modify Memory Allocation (SETBLOCK) 
 4Bh (75)                Load or Execute a Program (EXEC) 
 4Ch (76)                Terminate a Process (EXIT) 
 4Dh (77)                Get Return Code of a Subprocess (WAIT) 
 4Eh (78)                Find First Matching File (FIND FIRST) 
 4Fh (79)                Find Next Matching File (FIND NEXT) 
 50h (80)                Reserved 
 51h (81)                Reserved 
 52h (82)                Reserved 
 53h (83)                Reserved 
 54h (84)                Get VERIFY Setting 
 55h (85)                Reserved 
 56h (86)                Rename a File 
 57h (87)                Get or Set a File's Date and Time 
 59h (89)                Get Extended Error Information             ò DOS 3.0 
 5Ah (90)                Create Unique File                         ò DOS 3.0 
 5Bh (91)                Create New File                            ò DOS 3.0 
 5Ch (92)                Lock/Unlock File Access                    ò DOS 3.0 
 5Dh (93)                Reserved 
 5E00h (94-0)            Get Machine Name                           ò DOS 3.1 
 5E02h (94-2)            Set Printer Setup                          ò DOS 3.1 
 5E03h (94-3)            Get Printer Setup                          ò DOS 3.1 
 5F02h (95-2)            Get Redirection List Entry                 ò DOS 3.1 
 5F03h (95-3)            Redirect Device                            ò DOS 3.1 
 5F04h (95-4)            Cancel Redirection                         ò DOS 3.1 
 60h (96)                Reserved 
 61h (97)                Reserved 
 62h (98)                Get PSP Address                            ò DOS 3.0