                       Changes to ZPC.ASM for Version 2.1

        This  file documents changes made to ZPC.ASM to cause version 2.1 
        of ZPC to be produced when ZPC is assembled.  Sections containing 
        changed and/or added code are listed along with 3 lines above and 
        below each section of original unchanged code.

	*****************************************************************

	ADD	BX,4			;MOVE TO NEXT LINE (ONE SKIPPED)
	LOOP	ZPCLP			;FINISH MESSAGE
	CALL	TYPTX
	DB	27,'Y$;Z-100 PC Emulator, V 2.1.'
	IF	LEVEL1
	DB	'1'
	ENDIF

	*****************************************************************

	MOV	SI,OFFSET PTIMINT*4
	MOV	[SI],OFFSET INTRET
	MOV	2[SI],CS		;INSTALL PC SFWE. TIMER INT. RETURN

;	*** THIS SECTION, FOR NEW ZHS BOARD, CHANGED 10-6-86

	MOV	SI,OFFSET ETJINT*4	;POINT TO "JIMINY" INT. VECTOR
	CMP	CS:BYTE PTR ETFLG,0	;ET-100?
	JNZ	SJZ100			;YES
	MOV	SI,OFFSET ZJINT*4	;ELSE, USE Z-100 VECTOR
	MOV	WORD PTR -4[SI],OFFSET JVINT	;SET VIDEO INT VECTOR
	MOV	-2[SI],CS

SJZ100:	MOV	WORD PTR [SI],OFFSET JKINT	;SET NEW VECTOR
	MOV	2[SI],CS
	CMP	SI,OFFSET ZJINT*4	;ET-100?

	*****************************************************************

	AND	AL,0FFH-8		;UNMASK SLAVE PIC INPUT
	OUT	MASTER+1,AL
	IN	AL,SLAVE+1		;READ SLAVE PIC MASK

	AND	AL,3FH			;***UNMASK VECTOR INTERRUPTS 7 AND 6

	OUT	SLAVE+1,AL
	JMP	SHORT ZUM
UMET:	IN	AL,MASTER+1		;READ MASTER PIC MASK

	*****************************************************************

	OR	X10H,10B		;FLAG 8087 PRESENT
NO8087:
	ENDIF

;	*** CONTROL-C SECTION ADDED 9-11-86

	XOR	AX,AX
	MOV	DS,AX			;POINT TO INT. PAGE
	PUSH	CS
	POP	ES			;PUT ES HERE
	MOV	SI,23H*4		;CTLC VECTOR
	MOV	DI,OFFSET CTLCA		;PUT IT HERE
	MOVSW				;MOVE VECTOR
	MOVSW
	PUSH	CS
	POP	DS			;FIX DS

	MOV	DX,OFFSET INSMSG
	MOV	AH,9
	INT	21H			;SAY "ZPC INSTALLED"
                           