2F1900 INT 2F U - DOS 4.x only SHELLB.COM - INSTALLATION CHECK
2F1901 INT 2F U - DOS 4.x only SHELLB.COM - SHELLC.EXE INTERFACE
2F1902 INT 2F U - DOS 4.x only SHELLB.COM - COMMAND.COM INTERFACE
2F1903 INT 2F U - DOS 4.x only SHELLB.COM - COMMAND.COM interface
2F1904 INT 2F U - DOS 4.x only SHELLB.COM - SHELLB transient to TSR interface
2F1980 INT 2F U - IBM ROM-DOS v4.0 - INSTALLATION CHECK
2F1981 INT 2F U - IBM ROM-DOS v4.0 - GET ??? STRING
2F1982 INT 2F U - IBM ROM-DOS v4.0 - GET ??? TABLE