1 files changed, 2 insertions, 0 deletions
diff --git a/c/gbos.h b/c/gbos.h
index a0619cc..d207a75 100644
--- a/c/gbos.h
+++ b/c/gbos.h
@@ -13,6 +13,8 @@ char          readc(void);                /* one input byte, EOF at end    */
 void          sexit(unsigned char code);
 unsigned char getpid(void);
 unsigned char pipe(void);         /* -> read fd; write end is read+1 */
+void          ssend(unsigned char b);   /* link-port: transmit one byte */
+unsigned char srecv(void);              /* link-port: receive one byte (blocks) */
 
 /* helpers (c/libc.c) */
 void          putu(unsigned int n);              /* print decimal          */