X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=ROM2%2Fdisplay.c;h=da51973669f6d5c2516b726b62ceaabfcc3b4a20;hb=3781ef6863f304c8242fc1216cddbdbb0c74bebe;hp=af969218c349ad0603345891e8995de6165c03c8;hpb=1e7218d1311dafb5c1c81e4c4ad64847432be0b5;p=uccvend-snackrom.git

diff --git a/ROM2/display.c b/ROM2/display.c
index af96921..da51973 100644
--- a/ROM2/display.c
+++ b/ROM2/display.c
@@ -9,10 +9,12 @@
  *
  */
 
+#include "display.h"
 #include "vend.h"
 
 char display_buffer[10];    /* what each byte on the display reads          */
 char current_message[256];  /* message that is scrolled or switched between */
+u8   msg_length;            /* length of current_message                    */
 u8   wrap_mode;             /* whether to scroll or alternate between msgs  */
 u8   scroll_point;          /* how far through the message we have scrolled */
 
@@ -25,16 +27,35 @@ void set_msg(char* newmsg, u8 wrap) {
 	char* dest = current_message;
 	/* equivalent of a string copy */
 	/* while (dest++ = newmsg++); */
+	msg_length = 0;
 	while (newmsg) {
 		dest = newmsg;
 		dest++;
 		newmsg++;
+		msg_length++;
 	}
 	wrap_mode = wrap;
 	scroll_point = 0;
 	display_update();
 }
 
+void display_shift() {
+	/* update the display for WRAP_SCROLL or WRAP_ALTERNATE modes */
+	switch (wrap_mode) {
+		case WRAP_SCROLL:
+			scroll_point++;
+			if (scroll_point >= msg_length) scroll_point = 0;
+			display_update();
+			break;
+		case WRAP_ALTERNATE:
+			scroll_point += 10;
+			if (scroll_point >= msg_length) scroll_point = 0;
+			/* the above means that only sets of multiples of 10 characters
+			 * are shown (excess ones are not) */
+			display_update();
+	}
+}
+
 void set_char(char c, u8 pos) {
 	/* sets a single character */
 	display_buffer[pos] = c;
@@ -67,15 +88,16 @@ void display_reset() {
 
 void display_update() {
 	u8 i;
+
+	for (i=0; i < 10; i++) {
+		display_buffer[i] = current_message[(i+scroll_point)%msg_length];
+	}
+
+	/* hmmm, will this cause some flickering of the display? */
 	display_reset();
 	
 	for (i=0; i < 10; i++) {
-		/* FIXME: we may need to fiddle with the character codes sent to the 
-		 * controller. It doesn't seem like we have to, but datasheets for
-		 * the "pin-for-pin" compatible MSC1937 from OKI suggest a different
-		 * character set
-		 */
-		display_send_byte(i[display_buffer]&0x7f);
+		display_send_byte(display_buffer[i]&0x7f);
 	}
 }