Update nabu.asm

Ongoing work on NABU interrupt processing.

Co-Authored-By: Les Bird <lesbird65@gmail.com>

Source/HBIOS/nabu.asm

@@ -49,17 +49,7 @@ NABU_PREINIT:
 	; PORT A IN WRITE MODE AND SET ALL BITS TO ZERO
 	; PORT B IN READ MODE
 ;
-	; SET I/O PORT MODES
-	LD	A,7			; PSG R7 (ENABLE REG)
-	OUT	(NABU_RSEL),A		; SELECT IT
-	LD	A,%01000000		; PORT B INPUT, PORT A OUPUT
-	OUT	(NABU_RDAT),A		; SET IT
-;
-	; SET PORT A TO VALUE 0
-	LD	A,14			; PSG R16 (PORT A DATA)
-	OUT	(NABU_RSEL),A		; SELECT IT
-	XOR	A			; VALUE 0
-	OUT	(NABU_RDAT),A		; SET IT
+	CALL	NABU_SETPSG	
 ;
 	; ADD TO INTERRUPT CHAIN
 	LD	HL,NABU_STAT
@@ -69,26 +59,45 @@ NABU_PREINIT:
 NABU_INIT:
 	CALL	NEWLINE			; FORMATTING
 	PRTS("NABU: INT1$")
-	XOR	A
-	OUT	(NABU_INT1CLR),A
+;	XOR	A
+;	OUT	(NABU_INT1CLR),A
 	RET				; DONE
 ;
+NABU_SETPSG:
+	; SET I/O PORT MODES
+	LD	A,7			; PSG R7 (ENABLE REG)
+	OUT	(NABU_RSEL),A		; SELECT IT
+	LD	A,%01111111		; PORT B INPUT, PORT A OUPUT
+	OUT	(NABU_RDAT),A		; SET IT
+;
+;	; SET PORT A TO VALUE 0
+;	LD	A,14			; PSG R14 (PORT A DATA)
+;	OUT	(NABU_RSEL),A		; SELECT IT
+;	XOR	A			; VALUE 0
+;	OUT	(NABU_RDAT),A		; SET IT
+;
+	LD	A,15
+	OUT	(NABU_RSEL),A
+	IN	A,(NABU_RIN)
+	RET
+;
 ;  INTERRUPT ENTRY POINT
 ;
 NABU_STAT:
-	XOR	A
-	OUT	(NABU_INT1CLR),A	; CLEAR THE INTERRUPT
+	CALL	NABU_SETPSG
+;	XOR	A
+;	OUT	(NABU_INT1CLR),A	; CLEAR THE INTERRUPT
 	LD	HL,(NABU_TICCNT)	; INCREMENT NABU TICK COUNTER
 	INC	HL			; ... IN HBIOS PROXY
 	LD	(NABU_TICCNT),HL
-	LD	A,(NABU_HBTICK)		; INCREMENT INTERNAL TICK CTR
-	INC	A
-	LD	(NABU_HBTICK),A
-	CP	$0A			; CALL HB_TICK EVERY 10 INTERRUPTS (50HZ)
-	RET	NZ			; NOT TIME THEN JUST RETURN
+;	LD	A,(NABU_HBTICK)		; INCREMENT INTERNAL TICK CTR
+;	INC	A
+;	LD	(NABU_HBTICK),A
+;	CP	$0A			; CALL HB_TICK EVERY 10 INTERRUPTS (50HZ)
+;	RET	NZ			; NOT TIME THEN JUST RETURN
 	CALL	HB_TICK			; DO NORMAL HBIOS TICK
 	XOR	A
-	LD	(NABU_HBTICK),A		; RESET HBTICK COUNTER
+;	LD	(NABU_HBTICK),A		; RESET HBTICK COUNTER
 	INC	A			; INTERRUPT HANDLED
 	RET
 ;