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Implement selectable YM2612/YM3834 invalid status port behavior
author Michael Pavone <pavone@retrodev.com>
date Wed, 26 Feb 2020 22:40:37 -0800
parents 32a3aa7b4a45
children 508522f08e4d
comparison
equal deleted inserted replaced
1903:62166274e6c0 1904:8312e574100a
130 } 130 }
131 if (context->busy_start != CYCLE_NEVER && context->busy_start >= deduction) { 131 if (context->busy_start != CYCLE_NEVER && context->busy_start >= deduction) {
132 context->busy_start -= deduction; 132 context->busy_start -= deduction;
133 } else { 133 } else {
134 context->busy_start = CYCLE_NEVER; 134 context->busy_start = CYCLE_NEVER;
135 }
136 if (context->last_status_cycle != CYCLE_NEVER && context->last_status_cycle >= deduction) {
137 context->last_status_cycle -= deduction;
138 } else {
139 context->last_status = 0;
140 context->last_status_cycle = CYCLE_NEVER;
135 } 141 }
136 } 142 }
137 143
138 #ifdef __ANDROID__ 144 #ifdef __ANDROID__
139 #define log2(x) (log(x)/log(2)) 145 #define log2(x) (log(x)/log(2))
186 dfopen(debug_file, "ym_debug.txt", "w"); 192 dfopen(debug_file, "ym_debug.txt", "w");
187 memset(context, 0, sizeof(*context)); 193 memset(context, 0, sizeof(*context));
188 context->clock_inc = clock_div * 6; 194 context->clock_inc = clock_div * 6;
189 context->busy_cycles = BUSY_CYCLES * context->clock_inc; 195 context->busy_cycles = BUSY_CYCLES * context->clock_inc;
190 context->audio = render_audio_source(master_clock, context->clock_inc * NUM_OPERATORS, 2); 196 context->audio = render_audio_source(master_clock, context->clock_inc * NUM_OPERATORS, 2);
197 //TODO: pick a randomish high initial value and lower it over time
198 context->invalid_status_decay = 225000 * context->clock_inc;
199 context->status_address_mask = (options & YM_OPT_3834) ? 0 : 3;
191 200
192 //some games seem to expect that the LR flags start out as 1 201 //some games seem to expect that the LR flags start out as 1
193 for (int i = 0; i < NUM_CHANNELS; i++) { 202 for (int i = 0; i < NUM_CHANNELS; i++) {
194 if (options & YM_OPT_WAVE_LOG) { 203 if (options & YM_OPT_WAVE_LOG) {
195 char fname[64]; 204 char fname[64];
1115 } 1124 }
1116 } 1125 }
1117 } 1126 }
1118 } 1127 }
1119 1128
1120 uint8_t ym_read_status(ym2612_context * context, uint32_t cycle) 1129 uint8_t ym_read_status(ym2612_context * context, uint32_t cycle, uint32_t port)
1121 { 1130 {
1122 uint8_t status = context->status; 1131 uint8_t status;
1123 if (cycle >= context->busy_start && cycle < context->busy_start + context->busy_cycles) { 1132 port &= context->status_address_mask;
1124 status |= 0x80; 1133 if (port) {
1134 if (context->last_status_cycle != CYCLE_NEVER && cycle - context->last_status_cycle > context->invalid_status_decay) {
1135 context->last_status = 0;
1136 }
1137 status = context->last_status;
1138 } else {
1139 status = context->status;
1140 if (cycle >= context->busy_start && cycle < context->busy_start + context->busy_cycles) {
1141 status |= 0x80;
1142 }
1143 context->last_status = status;
1144 context->last_status_cycle = cycle;
1125 } 1145 }
1126 return status; 1146 return status;
1147
1127 } 1148 }
1128 1149
1129 void ym_print_channel_info(ym2612_context *context, int channel) 1150 void ym_print_channel_info(ym2612_context *context, int channel)
1130 { 1151 {
1131 ym_channel *chan = context->channels + channel; 1152 ym_channel *chan = context->channels + channel;
1234 save_int8(buf, context->selected_reg); 1255 save_int8(buf, context->selected_reg);
1235 save_int8(buf, context->selected_part); 1256 save_int8(buf, context->selected_part);
1236 save_int32(buf, context->current_cycle); 1257 save_int32(buf, context->current_cycle);
1237 save_int32(buf, context->write_cycle); 1258 save_int32(buf, context->write_cycle);
1238 save_int32(buf, context->busy_start); 1259 save_int32(buf, context->busy_start);
1260 save_int32(buf, context->last_status_cycle);
1261 save_int32(buf, context->invalid_status_decay);
1262 save_int8(buf, context->last_status);
1239 } 1263 }
1240 1264
1241 void ym_deserialize(deserialize_buffer *buf, void *vcontext) 1265 void ym_deserialize(deserialize_buffer *buf, void *vcontext)
1242 { 1266 {
1243 ym2612_context *context = vcontext; 1267 ym2612_context *context = vcontext;
1309 context->selected_reg = load_int8(buf); 1333 context->selected_reg = load_int8(buf);
1310 context->selected_part = load_int8(buf); 1334 context->selected_part = load_int8(buf);
1311 context->current_cycle = load_int32(buf); 1335 context->current_cycle = load_int32(buf);
1312 context->write_cycle = load_int32(buf); 1336 context->write_cycle = load_int32(buf);
1313 context->busy_start = load_int32(buf); 1337 context->busy_start = load_int32(buf);
1314 } 1338 if (buf->size > buf->cur_pos) {
1339 context->last_status_cycle = load_int32(buf);
1340 context->invalid_status_decay = load_int32(buf);
1341 context->last_status = load_int8(buf);
1342 } else {
1343 context->last_status = context->status;
1344 context->last_status_cycle = context->write_cycle;
1345 }
1346 }