From 65f351eccb34b310c15e3cd38dcae5b152187092 Mon Sep 17 00:00:00 2001 From: Bernard Blackham Date: Sun, 10 Aug 2003 07:45:58 +0000 Subject: [PATCH] Start of coin mech handler --- ROM2/coinmech.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) diff --git a/ROM2/coinmech.c b/ROM2/coinmech.c index 80a11a7..a5a38e0 100644 --- a/ROM2/coinmech.c +++ b/ROM2/coinmech.c @@ -1,2 +1,78 @@ #include "vend.h" +#define COINMECH_ID 0x20 + +u8 last_byte; + + +u8 parity_test(u8 c) { + u8 parity = 0; + for (parity = 0; c; c = c>>1) { + if (c&1) parity = !parity; + } + return parity; +} + +/* + * parity_good truth table: + * + * | parity_test(c) + * | 0 1 + * -----+--------- + * R8 0 | 1 0 + * 1 | 0 1 + */ + +bool parity_good(u8 c) { + 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_of(c)) + bset(&_io_ports[M6811_SCCR1], M6811_T8); + else + bclr(&_io_ports[M6811_SCCR1], M6811_T8); +} + +void ask_for_retrans() { + /* sends an 0xff down the line */ + send_byte(0xff); +} + + +u8 packet_pos = 0; + +#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 */ + ask_for_retrans(); + 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(x&0x10)) { + switch (in & 0x0f) { + } + } else { + + } +} -- 2.20.1