MASM 5.10 MACRO.DOC: Device I/O

ID Number: Q34469

5.10 | 5.10

MS-DOS | OS/2

Summary:

The following information was taken from the MASM 5.10 MACRO.DOC file.

More Information:

DEVICE I/O

@Read (3Fh)

Reads data from a file or device

Syntax: @Read &buffer, length [,[handle] [,segment]]

Arguments: buffer = Offset of buffer where data will

be stored

length = Length of data in bytes

handle = File or device handle; if none given,

keyboard (handle 0) is assumed

segment = Segment of address string (DS if not

given)

Return: If carry clear, bytes read in AX

Registers used: Always AX, DX, BX, and CX; DS if segment

changed

@Write (40h)

Writes data to a file or device

Syntax: @Write &buffer, length, [,[handle] [,segment]]

Arguments: buffer = Offset of buffer where data is

stored

length = Length of data in bytes

handle = File or device handle; if none given,

screen

(handle 1) is assumed

segment = Segment of address string (DS if not

given)

Return: If carry clear, bytes written in AX

Registers used: Always AX, DX, BX, and CX; DS if segment

changed