Wip writing SN76489 test sketch

arduino/SN76489-test/SN76489-test.ino

@@ -0,0 +1,24 @@
+/**
+ * SN76489 sound chip test
+ * 
+ * DATA BUS IS: 3, 4, 5, 6, 7, 8, 9, 10 (NOTE: 3 is D0, but D0 is the MSB)
+ * WE 11   (Active low)
+ */
+
+void setup() {
+    DDRD = DDRD | B11111000; // Port D (arduino pins 3 to 7) is output. In or to preserve serial pins and interrupt pin
+    DDRB = B00001111; // Port B (0,1,2,3) = pins 8,9,10,11 output (11 is WE)
+}
+
+void loop() {
+}
+
+
+
+void writeByte(byte b) {
+    // Split byte to two parts and write to data bus
+    PORTD = b << 3;
+    PORTB = b >> 5;
+    // Pulse WE
+    b
+}