Int 21/AH=3Fh

Trusted Access - NB.SYS - GET STATE

AH = 3Fh
BX = file handle for device "$$NB$$NB"
CX = 0002h (size of state)
DS:DX -> buffer for state record (see #01414)

Return:
CF clear if successful
AX = number of bytes actually read (0 if at EOF before call)
CF set on error
AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)

Program: Trusted Access is a security and access-control package by Lassen Software, Inc.; NB.SYS is a device driver to prevent the user from terminating CONFIG.SYS or AUTOEXEC.BAT with Ctrl-Break

See Also: AH=40h"NB.SYS" - AX=4101h

Format of Trusted Access state record: Offset Size Description (Table 01414) 00h BYTE 00h off, 01h on 01h BYTE keys being disabled

bit 0:
Ctrl-Break

bit 1:
SysReq

bit 2:
Ctrl and Alt

bit 3:
Ctrl-Alt-Del

bit 7:
All keys (overrides other bits)

Category: Security - Int 21h - T

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