INT 2F - 4DOS.COM v2.1+ - API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. AX = D44Dh BH = function 00h installation check Return: AX = 44DDh BL = major version number BH = minor version number CX = PSPsee Program Segment Prefix segment address for current invocation DL = 4DOS shell number (0 for the first (root) shell, updated each time a new copy is loaded) 01h (internal, v2.1-3.03) terminate current copy of 4DOS Return: nothing (internal, v4.0+) ??? Return: AX = 44DDh ES:BX -> data area (see #03086) 02h ??? DX = ??? Note: v5.52 signals "unrecoverable error" and then terminates with INT 21/AH=4Ch or enters a deliberate infinite loop if ??? ---v2.1-3.03 only--- 03h EXEC program CX:DX -> EXEC record (see #03087) FEh deallocate shell number (passed through to root shell) ??? FFh allocate shell number (passed through to root shell) ---v5.52--- 03h get ??? BL = ??? (00h/01h) Return: DX = current value of ??? 04h set ??? BL = ??? (00h/01h) DX = new value for ??? Note: a bug in v3.00 will crash the system if unrecognized value in BH SeeAlso: AX=D44Eh,AX=D44Fh/BX=0000h,AX=E44Dh,INT 21/AX=4403h"DOS" SeeAlso: INT 14/AX=7000h Index: installation check;4DOS|installation check;NDOS Format of 4DOS v4.0 data area: Offset Size Description (Table 03086) 00h 2 BYTEs ??? 06h WORD XMSsee Extended Memory Specification handle for swapping ??? SeeAlso: #03087 Format of 4DOS EXEC v2.1-v3.03 record: Offset Size Description (Table 03087) 00h WORD offset of ASCIZA NUL-terminated ASCII string. The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h. Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. program name in same segment as EXEC record 02h WORD offset of DOS commandline in same segment as EXEC record 04h WORD segment of environment for child process (see INT 21/AH=26h) SeeAlso: #03086