started separating 'printf' as debug-only routine

c64/kernal/print_hex_byte.s

@@ -0,0 +1,48 @@
+
+//
+// Print the hex value in .A as two digits
+//
+
+print_hex_byte:
+
+#if HAS_BCD_SAFE_INTERRUPTS
+
+	// Idea by Haubitze
+
+	sed
+	pha
+	lsr
+	lsr
+	lsr
+	lsr
+	cmp #$0A
+	adc #$30
+	jsr JCHROUT
+	pla
+	and #$0F
+	cmp #$0A
+	adc #$30
+	cld
+	jmp JCHROUT
+
+#else
+
+	pha
+	lsr
+	lsr
+	lsr
+	lsr
+	ora #$30
+	cmp #$3A
+	bcc !+
+	adc #6
+!:	jsr JCHROUT
+	pla
+	and #$0f
+	ora #$30
+	cmp #$3A
+	bcc !+
+	adc #6
+!:	jmp JCHROUT
+
+#endif