Adding CBM510 support

git-svn-id: svn://svn.cc65.org/cc65/trunk@913 b7a2c559-68d2-44c3-8de9-860c34a00d81
2001-09-13 21:37:59 +00:00
parent 7f88d979f6
commit 14f2349ea1
8 changed files with 498 additions and 6 deletions
--- a/libsrc/cbm510/kirq.s
+++ b/libsrc/cbm510/kirq.s
@@ -0,0 +1,100 @@
+;
+; Ullrich von Bassewitz, 28.09.1998
+;
+; IRQ routine for the 510.
+;
+
+ 	.export	  	irq, nmi, k_irq, k_nmi
+	.import		k_scnkey, k_udtim, k_rs232
+	.importzp     	tpi1
+
+	.include      	"zeropage.inc"
+	.include	"io.inc"
+	.include	"page3.inc"
+
+
+; -------------------------------------------------------------------------
+; This is the mapping of the active irq register of the	6525 (tpi1):
+;
+; Bit   7       6       5       4       3       2       1       0
+;                               |       |       |       |       ^ 50 Hz
+;                               |       |       |       ^ SRQ IEEE 488
+;                               |       |       ^ cia
+;                               |       ^ IRQB ext. Port
+;                               ^ acia
+
+
+
+; -------------------------------------------------------------------------
+; IRQ entry point
+
+.proc	irq
+
+	pha
+        txa
+        pha
+        tya
+        pha
+	tsx
+	lda	$104,x	    		; Get the flags from the stack
+	and	#$10	    		; Test break flag
+	bne	L1
+	jmp	(IRQVec)
+L1:	jmp	(BRKVec)
+
+.endproc
+
+; -------------------------------------------------------------------------
+; NMI entry point
+
+.proc	nmi
+
+	jmp	(NMIVec)
+
+.endproc
+
+
+; -------------------------------------------------------------------------
+; Kernal irq entry point. The IRQvec points here (usually).
+
+k_irq:
+	lda     IndReg                  ; Ind. Segment retten
+        pha
+        cld
+	lda	#$0F
+	sta	IndReg
+	ldy	#tpiActIntReg
+	lda	(tpi1),y		; Interrupt Register 6525
+	beq	noirq
+
+; -------------------------------------------------------------------------
+; 50/60Hz interrupt
+
+	cmp	#%00000001		; ticker irq?
+	bne	irq1
+	jsr     k_scnkey		; Poll the keyboard
+        jsr	k_udtim			; Bump the time
+
+; -------------------------------------------------------------------------
+; UART interrupt
+
+irq1:	cmp	#%00010000		; interrupt from uart?
+     	bne	irqend
+	jsr	k_rs232			; Read character from uart
+
+; -------------------------------------------------------------------------
+; Done
+
+irqend:	ldy	#tpiActIntReg
+       	sta	(tpi1),y		; Clear interrupt
+
+noirq:	pla
+        sta     IndReg
+        pla
+        tay
+        pla
+        tax
+        pla
+k_nmi:	rti
+
+