diff --git a/protocol/x68k.c b/protocol/x68k.c
index d17af51c..b54e3d9a 100644
--- a/protocol/x68k.c
+++ b/protocol/x68k.c
@@ -64,6 +64,12 @@ uint8_t x68k_recv(void)
     return data;
 }
 
+void x68k_send(uint8_t d)
+{
+    while (!(UCSR1A&(1<<UDRE1)));
+    UDR1 = d;
+}
+
 // USART RX complete interrupt
 ISR(KBD_RX_VECT)
 {
diff --git a/protocol/x68k.h b/protocol/x68k.h
index 2cfda63a..0d9c7de8 100644
--- a/protocol/x68k.h
+++ b/protocol/x68k.h
@@ -41,6 +41,7 @@ POSSIBILITY OF SUCH DAMAGE.
 /* host role */
 void x68k_init(void);
 uint8_t x68k_recv(void);
+void x68k_send(uint8_t d);
 
 /* device role */