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) v1.1 - "API-REGISTER" - INITIALIZE CAPI
	AH = 01h
	ES:BX -> buffer for CAPI's use (refer to note below)
	CX = minimum number of pending messages
	DX = maximum simultaneous Level 3 connections
	SI = maximum concurrent received B3 data blocks
	DI = maximum B3 data block size
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 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 replaced by the
	  signature bytes "IA"
	the maximum length of a message is fixed at 180 bytes; the standard
	  document suggests using CX=10, DI=1, SI=7, and DI=130 for
	  applications which use only a single connection and standard
	  protocols
	the total size of the application-provided buffer must be at least
	  180*CX + DX*SI*DI bytes
SeeAlso: AH=02h,INT F1/AL=01h
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.