INT 2F,0 - DOS Multiplex Interrupt - Get Installed State

AL = 00

AH = 00 DOS 2.x PRINT.COM (undocumented, see note below)

01 PRINT (undocumented behavior also, see note below)

05 Critical error handler (undocumented DOS 3.0+)

06 ASSIGN (see note)

08 DRIVER.SYS (undocumented DOS 3.2+)

10 SHARE

11 Redirector/IFS is resident

12 MultiDOS is resident

13 Swap 13h and 19h

14 NLSFUNC

15 GRAPHICS.COM (see note below)

MS CD-ROM extension (MSCDEX) (see note below)

16 Windows 386

17 DOS shell

19 SHELLB.COM (DOS 4.0 only)

1A ANSI.SYS (DOS 4.0+)

1B XMA2EMS.SYS

40 OS/2 compatibility box

43 Himem XMS driver

7A Novell Netware IPX

AD DISPLAY.SYS internal (DOS 3.3+)

AE DOS installable command extension (DOS 3.3+)

B0 GRAFTABL.COM (DOS 3.3+)

B4 IBM 3270 emulation

B7 APPEND (DOS 3.3+)

B8 LAN existence

B9 LAN RECEIVER.COM

BF LAN REDIRIFS.EXE

C0-FF reserved for user applications

on return:

AL = 00 not installed, ok to install

= 01 not installed, do NOT install

= FF installed

- the installed test for append returns non-zero if installed;

zero if not installed

- AH = 00 and 01 are used by DOS 2.x PRINT.COM and is not a check

for installed state, see BIBLIO reference to "Undocumented DOS"

- ASSIGN returns non-zero if installed

- installation checks with AH=15 do not follow the standard format;

- see ~Bibliography~ reference to "Undocumented DOS"