X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=ROM2%2Fstart.s;h=7611f1b388ed995df3a145e5f286b69f6be09316;hb=27fb8a023fa0572ef4171624781460bc59537d49;hp=c37026396bd7ad4f54fd1a81b0e2871dfa16c8e4;hpb=41ad37ba6d86ccc4f8f720cb09f7891ae166cb38;p=uccvend-snackrom.git

diff --git a/ROM2/start.s b/ROM2/start.s
index c370263..7611f1b 100644
--- a/ROM2/start.s
+++ b/ROM2/start.s
@@ -2,6 +2,18 @@
 .globl _start
 
 _start:
+	;; set port a to output
+	ldab #0xfc  ; 11111000
+	stab 0x1001
+
+	;; turn display on
+	ldx #0x1000
+	bset 00,x #0x80
+
+	;; start chiming
+	ldx #0x1000
+	bset 00,x #0x10
+
 	;; enable the RTI
 	ldaa #0x40
 	staa 0x1024
@@ -12,14 +24,22 @@ _start:
 
 	;; set RTI intervals, and PA3/7 DDRs
 	ldaa #0x81
-	staa 0x1026
+	staa 0x1026  ;; RTI interval becomes E/2^14 = 6.6ms (or 150 Hz)
+
+	;; stop chiming
+	ldx #0x1000
+	bclr 00,x #0x10
 
 	;; clear ADC register
 	clra
 	staa 0x1030
 
 	;; set the stack pointer
-	lds _stack
+	lds #_stack
+
+	;; start chiming
+	ldx #0x1000
+	bset 00,x #0x10
 
 	;; blank initialised variables - should match memory.x's page0
 	ldx #0x0000
@@ -31,6 +51,20 @@ loop1:
 	bra loop1
 out1:
 
+	;; wait a while
+	ldx #0x0000
+loop2:
+	cpx #0x00ff
+	bcc out2
+	clr 00,x
+	inx
+	bra loop2
+out2:
+
+	;; stop chiming
+	ldx #0x1000
+	bclr 00,x #0x10
+
 	jsr main
 
 infinity: