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Bitfields for device attributes (character device)

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Bit Description

15

set (indicates character device)

14

IOCTL supported (see AH=44h)

13

(DOS 3.0+) output until busy supported

12

reserved

11

(DOS 3.0+) OPEN/CLOSE/RemMedia calls supported

10 - 8

reserved

7

(DOS 5.0+) Generic IOCTL check call supported (driver command 19h) (see AX=4410h,AX=4411h)

6

(DOS 3.2+) Generic IOCTL call supported (driver command 13h) (see AX=440Ch,AX=440Dh"DOS 3.2+")

5

reserved

4

device is special (use INT 29 "fast console output")

3

device is CLOCK$ (all reads/writes use transfer record described below)

2

device is NUL

1

device is standard output

0

device is standard input

Note:

For European MS-DOS 4.0, bit 11 also indicates that bits 8-6 contain a version code (000 = DOS 3.0,3.1; 001 = DOS 3.2; 010 = European DOS 4.0).

See Also:

#01648,#01646