- [CHG] Mòdul zxscreen renombrat a zx_screen

- [NEW] Les coses de la ULA ara estàn en el modul zx_ula
- [NEW] zx_screen ja agafa el color del borde de la ULA

zx_ula.cpp

@@ -0,0 +1,22 @@
+#include "zx_ula.h"
+
+namespace zx_ula
+{
+    static uint8_t border_color = 0;
+    static uint8_t ear = 0;
+    static uint8_t mic = 0;
+
+    int port_in()
+    {
+        return 0;
+    }
+
+    void port_out(int val)
+    {
+        border_color = val & 0x7;
+        mic = (val>>3)&0x1;
+        ear = (val>>4)&0x1;
+    }
+
+    uint8_t get_border_color() { return border_color; }
+}