X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=ROM2%2Fcoinmech.c;h=a6c0e51989248fba35c6f71d728f603d45b2809c;hb=5266fabbd6d0e04a49e31b945b3f3c96fbd12db6;hp=80a11a76d6b75cd4b4f61e4471986783c15b1097;hpb=4f35424978e202fff48c2331eee9fd01e3da244f;p=uccvend-snackrom.git

diff --git a/ROM2/coinmech.c b/ROM2/coinmech.c
index 80a11a7..a6c0e51 100644
--- a/ROM2/coinmech.c
+++ b/ROM2/coinmech.c
@@ -1,2 +1,132 @@
+#include "coinmech.h"
 #include "vend.h"
 
+#define COINMECH_ID   0x20
+
+volatile u8 last_byte;
+volatile u8 packet_pos = 0;
+volatile u16 value_1 = 0;
+volatile u8 value_2 = 0;
+volatile u8 dec_point = 0; 
+
+volatile u16 coin_value = 0;
+u8 item_cost = 0;
+volatile bool have_change = 0;
+
+u8 parity_test(u8 c) {
+	u8 parity = 0;
+	for (parity = 0; c; c = c>>1) {
+		if (c&1) parity = !parity;
+	}
+	return parity;
+}
+
+bool parity_good(u8 c) {
+
+/*
+ * parity_good truth table:
+ *
+ *      | parity_test(c)
+ *      | 0   1
+ * -----+---------
+ * R8 0 | 1   0
+ *    1 | 0   1
+ *
+ * equates to even parity?
+ */
+
+	u8 R8 = (_io_ports[M6811_SCCR1] & M6811_R8)?1:0;
+	u8 p = parity_test(c)?1:0;
+	return R8 == p;
+}
+
+void send_byte(u8 c) {
+	last_byte = c;
+	while (!(_io_ports[M6811_SCSR] & M6811_TDRE)); /* wait for TD register empty */
+
+	if (parity_test(c))
+		bset((void*)&_io_ports[M6811_SCCR1], M6811_T8);
+	else
+		bclr((void*)&_io_ports[M6811_SCCR1], M6811_T8);
+}
+
+#define IS_CTRL(x) (x & 0x10) /* true if this packet is a control packet */
+void sci_interrupt() {
+	u8 in;
+	in = _io_ports[M6811_SCDR];
+	
+	/* test for framing errors & parity bit */
+	if (_io_ports[M6811_SCSR] & M6811_FE || !parity_good(in)) {
+		_io_ports[M6811_SCDR]; /* read of register req'd to clear FE */
+		send_byte(0xff); /* request a retransmit */
+		return;
+	}
+
+	/* all bytes must have the correct ID in the 3 MSBs */
+	if ((in & 0xe0) != COINMECH_ID) return;
+
+	/* we have a good packet */
+	if (in == 0x3f) {
+		/* retransmit was requested */
+		send_byte(last_byte);
+		return;
+	}
+
+	if (packet_pos != 0 || IS_CTRL(in&0x10)) {
+		in &= 0x0f;
+		switch (in) {
+			case 0x01: 
+				/* just reply with ack */
+				/* original firmware does something with link master price holding */
+				send_byte(0x00);
+			case 0x02:
+				/* write back how much change to give, or 0xfe to hold it. */
+				if (item_cost) {
+					send_byte(item_cost / value_2);
+				} else
+					send_byte(0xfe);
+				break;
+			case 0x03:
+				/* hmmm, maybe we're sposed to do something here. firmware doesnt */
+				/* and just sets a random bit - something like "changer in use"?  */
+				break;
+			case 0x08:
+				/* start of packet */
+				packet_pos = 1;
+				send_byte(0x00);
+				break;
+			default:
+				/* just ack it and move on */
+				send_byte(0x00);
+		}
+	} else {
+		in &= 0x0f;
+		switch (packet_pos) {
+			case 1: value_1  = in;           break;
+			case 2: value_1 |= in << 4;      break;
+			case 3: value_1 |= in << 8;      break;
+			case 4: value_1 |= in << 12;     break;
+			case 5: value_2  = in;           break;
+			case 6: value_2 |= in << 4;      break;
+			case 7: dec_point = in;          break;
+			case 8: have_change = (in&0x01); break;
+			default:
+					if (packet_pos == 9) {
+						packet_pos = 0;
+						coin_value = value_1*value_2;
+					}
+					/* hmmm, else? */
+		}
+		packet_pos++;
+		send_byte(0x00); /* ack */
+	}
+}
+
+void coin_eat() {
+	coin_cost(coin_value); /* eat everything */
+}
+
+void coin_cost(u16 cost) {
+	item_cost = cost;
+	while(coin_value); /* wait until coin mech cleared */
+}