diff --git a/firmware/src_simtrace/iso7816_uart.h b/firmware/src_simtrace/iso7816_uart.h
deleted file mode 100644
index ed1c898a..00000000
--- a/firmware/src_simtrace/iso7816_uart.h
+++ /dev/null
@@ -1,6 +0,0 @@
-
-void iso_uart_dump(void);
-void iso_uart_rst(unsigned int state);
-void iso_uart_rx_mode(void);
-void iso_uart_clk_master(unsigned int master);
-void iso_uart_init(void);
diff --git a/firmware/src_simtrace/ringbuffer.c b/firmware/src_simtrace/ringbuffer.c
index f6e9985f..ae3ba715 100644
--- a/firmware/src_simtrace/ringbuffer.c
+++ b/firmware/src_simtrace/ringbuffer.c
@@ -14,6 +14,11 @@ uint8_t rbuf_read(volatile ringbuf *rb)
     return val;
 }
 
+uint8_t rbuf_peek(volatile ringbuf *rb)
+{
+    return rb->buf[rb->ird];
+}
+
 void rbuf_write(volatile volatile ringbuf *rb, uint8_t item)
 {
     if(!rbuf_is_full(rb)) {
diff --git a/firmware/src_simtrace/ringbuffer.h b/firmware/src_simtrace/ringbuffer.h
index 771c73f6..0cd82646 100644
--- a/firmware/src_simtrace/ringbuffer.h
+++ b/firmware/src_simtrace/ringbuffer.h
@@ -15,6 +15,7 @@ typedef struct ringbuf {
 
 void rbuf_reset(volatile ringbuf *rb);
 uint8_t rbuf_read(volatile ringbuf *rb);
+uint8_t rbuf_peek(volatile ringbuf *rb);
 void rbuf_write(volatile ringbuf *rb, uint8_t item);
 bool rbuf_is_empty(volatile ringbuf *rb);
 bool rbuf_is_full(volatile ringbuf *rb);