Format of interrupt sharing protocol interrupt handler entry point:
Offset	Size	Description	)
 00h  2 BYTEs	short jump to actual start of interrupt handler, immediately
		  following this data block (EBh 10h)
 02h	DWORD	address of next handler in chain
 06h	WORD	signature 424Bh
 08h	BYTE	EOI flag
		00h software interrupt or secondary hardware interrupt handler
		80h primary hardware interrupt handler (will issue EOI to
		      interrupt controller)
 09h  2 BYTEs	short jump to hardware reset routine
		must point at a valid FAR procedure (may be just RETF)
 0Bh  7 BYTEs	reserved (0) by IBM for future expansion
Note:	when chaining to the prior handler, the interrupt handler must perform
	  an indirect jump/call using the address at offset 02h in the
	  ISP header.  This permits another AMIS TSR to hook itself into
	  the chain at a position other than as the first handler to receive
	  an interrupt.
SeeAlso: INT F1/AH=01h"Common ISDN API",INT F1/AH=06h"CAPI",#04068