INT F1 - Common ISDN 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. (CAPI) v2.0 - "CAPI_REGISTER" - INITIALIZE CAPI AL = 01h AH = CAPI version number * 10 (14h for v2.0) ES:BX -> buffer for CAPI's use (refer to note below) CX = number of bytes for message buffer DX = maximum simultaneous logical (Level 3) connections SI = maximum concurrent received B3 data blocks (min. 2) DI = maximum B3 data block size (up to 2048 bytes) Return: AX = CAPI-assigned application ID 0000h on error BX = error number 1001h registration error Range: INT 00 to INT FF, selectable by program parameter Notes: the caller is required to provide at least 512 bytes of stack space the CAPI interrupt handler begins with a header (see #04068) which is nearly identical to the IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. Interrupt Sharing Protocol header (see #02568 at INT 2D"AMISAlternate Multiplex Interrupt Specification"), except that the short jump instruction to a hardware reset handler at offset 09h is zeroed out and the entire header is inexplicably shortened by one byte the standard document suggests using 1024 + (1024*DX) bytes for the message buffer for typical applications the total size of the application-provided buffer must be at least CX + DX*SI*DI bytes SeeAlso: AH=01h,INT F1/AL=02h Index: installation check;Common ISDN 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. Format of CAPI v2.0 interrupt handler entry point: Offset Size Description (Table 04068) 00h 2 BYTEs short jump to actual start of interrupt handler, immediately following this data block (EBh 0Fh) 02h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of next handler in chain 06h WORD signature 424Bh 08h BYTE EOI(End of Interrupt) A particular command sent to the interrupt controller to indicate that the interrupt has been handled by software and that new interrupts of the same or lower priority may now be signalled by the interrupt controller. flag (80h) 80h primary hardware interrupt handler (will issue EOI(End of Interrupt) A particular command sent to the interrupt controller to indicate that the interrupt has been handled by software and that new interrupts of the same or lower priority may now be signalled by the interrupt controller.) 09h 2 BYTEs reserved (0) (is short jump to hardware reset routine in ISP header) 0Bh 4 BYTEs signature "CAPI" 0Fh 2 BYTEs two-digit CAPI version number in ASCII ('20') SeeAlso: #02568 at INT 2D