Added an interface to support multiple games

- In the same way, I expect the addition of the ability of holding
multiple sinks in memory like outputting to a TUI, GUI and other
hardware devices

esdi.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"log"
+
+	"github.com/tarm/serial"
+)
+
+type ESDI struct {
+	SerialConfig *serial.Config
+	SerialConn   *serial.Port
+	Source       GameSource
+}
+
+func (e *ESDI) Close() {
+	err := e.SerialConn.Close()
+	if err != nil {
+		log.Fatalf("couldn't close serial connection: %v", err)
+	}
+}
+
+func ESDIInit(port string, baud int) (ESDI, error) {
+	sConfig := &serial.Config{
+		Name: port,
+		Baud: baud,
+	}
+
+	// Open the serial port
+	sPort, err := serial.OpenPort(sConfig)
+	if err != nil {
+		return ESDI{}, err
+	}
+
+	return ESDI{sConfig, sPort, nil}, nil
+}