IN: DL ASCII character to print. OUT: Nothing.Prints the character in DL to the standard output device (usually CON: if not redirected.)
IN: Nothing. OUT: AL Character from device.Gets the next character from the standard input device (usually CON: if not redirected.)
IN: DS:DX --> ASCII$ string to print. OUT: Nothing.Prints the dollar-terminated string to the standard output device.
IN: AL INT number. DS:DX INT vector. OUT: Nothing.Sets the specified interrupt vector to the value held in DS:DX.
IN: Nothing. OUT: AL Major version number. AH Minor version number.Used to return the current DOS version number.
IN: AL Program return code. DX Memory to reserve in paragraphs. OUT: Nothing.Terminate program but remain in memory using DX paragraphs.
IN: AL INT number. OUT: ES:BX INT vector.Sets ES:BX to the value of the specified interrupt vector.
IN: AL 00h Get switch character. 01h Set switch character. DL Switch character if AL=01h OUT: DL Switch character if AL=00hGets or sets the current character to be used as a switch on the command line (usually '/'.)
IN: AL 00h Get file attributes. 01h Set file attributes. CX New attribute if AL=01. DS:DX --> ASCIIZ filename. OUT: CX File attribute if getting attribute. AX Error code if error. CARRY Set if error.Gets or sets attributes for the file whose name is pointed to by DS:DX. Can be used to check for file's existence.
IN: BX Number of paragraphs required. OUT: AX Segment of block if successful. Error code if error. BX Size of largest available block if error. CARRY Set if error.Attempts to allocate memory to the current procedure.
IN: ES Segment of block to be released. OUT: AX Error code if error. CARRY Set if error.Attempts to release the memory block pointed to by ES back to the main pool.
IN: ES Segment of block to be modified. BX New size in paragraphs. OUT: AX Error code if error. BX Size of largest available block if error. CARRY Set if error.Attempts to change the size of the specified memory block to the length in BX.
IN: AL 00h Load and execute program. 03h Load overlay. DS:DX --> ASCIIZ filename. ES:BX --> Parameter block. For AL=03h, parameter block consists of: +00 Word Segment address to load overlay. +02 Word Relocation factor.Loads program into memory and then executes if AL=00h.
IN: AL Program return code. OUT: Nothing.Terminate program and return code in AL to parent.
IN: BX Segment address of new PSP.Sets the current PSP to the one specified in BX.
IN: Nothing. OUT: ES:BX --> Invar.Gets pointer to DOS table 'invar'. See Appendix 2 for details.
IN: DS:SI --> BPB to expand. ES:BP --> Block header to fill in. OUT: Nothing.Fills in block header with information from BPB.
IN: DX Segment address of new PSP. SI Value to put in new PSP:0002 (top of mem segment.) OUT: Nothing.Creates a child PSP at the address specified.
IN: AL 00h Get strategy. 01h Set strategy. BX New strategy code if AL=01h. OUT: AX Strategy code if AL was 00h Strategy codes: 0000 - First fit. 0001 - Best fit. 0002 - Last fit.Gets or sets memory allocation strategy for subsequent memory requests.
IN: AL 00h DS:DX --> Buffer to receive string. OUT: AX Error code if error. CH 00h if name not defined. >00h if name defined. CL NETBIOS name number if CH>0 CARRY Set if error.Gets machine name (MS-NET only.)
IN: AL 02h BX Redirection list index. DS:SI --> Buffer to receive 16-byte device name. ES:DI --> Buffer to receive 128-byte shortname. OUT: CARRY Set if error. AX Error code if error. If not error: BH Device status flag. bit 0 0 device valid. 1 device invalid. BL Device type. 03h Printer. 04h Drive. CX Stored parameter value. DX, BP Destroyed.Gets entry number BX in the list of redirections.
IN: AL 03h BL Device type. 03h Printer. 04h Drive. CX Parameter to save for caller. DS:SI --> ASCIIZ local device name. ES:DI --> ASCIIZ shortname followed by ASCIIZ password. OUT: CARRY Set if error. AX Error code if error.Attempt to connect device to network shortname, using given password.
IN: AL 04h DS:SI --> ASCIIZ local device name. OUT: CARRY Set if error. AX Error code if error.Disconnect device from network.
IN: DS:SI --> Source pathname. ES:DI --> Buffer to hold destination pathname. OUT: CARRY Set if error. AX Error code if error.Gives true pathname, taking into account current drive and directory. Gives error if goes above root (i.e. too many '\..\'.)
IN: Nothing. OUT: BX Segment address of current PSP.Gets the segment address of the PSP of the current process.