--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ymf262.c	Sun Jan 19 00:31:16 2025 -0800
@@ -0,0 +1,129 @@
+#include <stdlib.h>
+#include <string.h>
+#include "ymf262.h"
+#include "render_audio.h"
+
+void ymf262_init(ymf262_context *context, uint32_t master_clock, uint32_t clock_div, uint32_t options)
+{
+	memset(context, 0, sizeof(*context));
+	context->clock_inc = clock_div * 8;
+	context->audio = render_audio_source("YMF262", master_clock, context->clock_inc * OPL3_NUM_OPERATORS, 2);
+	ymf262_reset(context);
+}
+
+void ymf262_reset(ymf262_context *context)
+{
+	//TODO: implement me
+}
+
+void ymf262_free(ymf262_context *context)
+{
+	render_free_source(context->audio);
+	free(context);
+}
+
+void ymf262_adjust_master_clock(ymf262_context *context, uint32_t master_clock)
+{
+	render_audio_adjust_clock(context->audio, master_clock, context->clock_inc * OPL3_NUM_OPERATORS);
+}
+
+void ymf262_adjust_cycles(ymf262_context *context, uint32_t deduction)
+{
+	context->cycle -= deduction;
+}
+
+void ymf262_run(ymf262_context *context, uint32_t to_cycle)
+{
+	for (; context->cycle < to_cycle; context->cycle += context->clock_inc)
+	{
+		context->current_op++;
+		if (context->current_op == OPL3_NUM_OPERATORS) {
+			context->current_op = 0;
+			int16_t left = 0, right = 0;
+			render_put_stereo_sample(context->audio, left, right);
+		}
+	}
+}
+
+void ymf262_address_write_part1(ymf262_context *context, uint8_t address)
+{
+	context->selected_reg = address;
+	context->selected_part = 0;
+}
+void ymf262_address_write_part2(ymf262_context *context, uint8_t address)
+{
+	context->selected_reg = address;
+	context->selected_part = 0;
+}
+
+#define OPL3_NTS 0x08
+
+void ymf262_data_write(ymf262_context *context, uint8_t value)
+{
+	if (!context->selected_reg) {
+		return;
+	}
+	uint8_t old = 0;
+	if (context->selected_reg >= OPL3_PARAM_START && context->selected_reg < OPL3_PARAM_END) {
+		if (context->selected_part) {
+			old = context->part2_regs[context->selected_reg - OPL3_PARAM_START];
+			context->part2_regs[context->selected_reg - OPL3_PARAM_START] = value;
+		} else {
+			old = context->part1_regs[context->selected_reg - OPL3_PARAM_START];
+			context->part1_regs[context->selected_reg - OPL3_PARAM_START] = value;
+		}
+	} else if (context->selected_part) {
+		if (context->selected_reg <= sizeof(context->timer_test)) {
+			old = context->timer_test[context->selected_reg - 1];
+			context->timer_test[context->selected_reg - 1] = value;
+		} else if (context->selected_reg == OPL3_NTS) {
+			old = context->nts;
+			context->nts = value;
+		} else {
+			return;
+		}
+	} else {
+		switch (context->selected_reg)
+		{
+		case 0x01:
+			old = context->part2_test;
+			context->part2_test = value;
+			break;
+		case 0x04:
+			old = context->connection_sel;
+			context->connection_sel = value;
+			break;
+		case 0x05:
+			old = context->opl3_mode;
+			context->opl3_mode = value;
+			break;
+		default:
+			return;
+		}
+	}
+	if (value != old) {
+		if (context->vgm) {
+			if (context->selected_reg) {
+				vgm_ymf262_part2_write(context->vgm, context->cycle, context->selected_reg, value);
+			} else {
+				vgm_ymf262_part1_write(context->vgm, context->cycle, context->selected_reg, value);
+			}
+		}
+	}
+}
+
+void ymf262_vgm_log(ymf262_context *context, uint32_t master_clock, vgm_writer *vgm)
+{
+	vgm_ymf262_init(vgm, 8 * master_clock / context->clock_inc);
+	context->vgm = vgm;
+	//TODO: write initial state
+}
+
+uint8_t ymf262_read_status(ymf262_context *context, uint32_t cycle, uint32_t port)
+{
+	if (port) {
+		//TODO: Investigate behavior of invalid status reads
+		return 0xFF;
+	}
+	return context->status;
+}