diff --git a/src/fpga.c b/src/fpga.c
index 61e9d81..f6f7cf5 100644
--- a/src/fpga.c
+++ b/src/fpga.c
@@ -42,12 +42,10 @@
 #include "fpga_spi.h"
 #include "config.h"
 #include "uart.h"
-#include "sdcard.h"
 #include "diskio.h"
 #include "integer.h"
 #include "ff.h"
 #include "fileops.h"
-// XXX #include "fpga_spi.h"
 #include "spi.h"
 #include "led.h"
 #include "timer.h"
@@ -100,8 +98,6 @@ void fpga_pgm(uint8_t* filename) {
   uint8_t data;
   int i;
   tick_t timeout;
-//  UINT bytes_read;
-//  uint16_t j;
   do {
     i=0;
     timeout = getticks() + 100;
@@ -152,8 +148,6 @@ void fpga_rompgm() {
   uint8_t data;
   int i;
   tick_t timeout;
-//  UINT bytes_read;
-//  uint16_t j;
   do {
     i=0;
     timeout = getticks() + 100;
diff --git a/src/msu1.c b/src/msu1.c
index 179810c..8a426f1 100644
--- a/src/msu1.c
+++ b/src/msu1.c
@@ -122,7 +122,7 @@ int msu1_loop() {
       msu_track = get_msu_track();
       printf("Audio requested! Track=%d\n", msu_track);
 
-      /* open file */
+      /* open file, fill buffer */
       f_close(&file_handle);
       snprintf(suffix, sizeof(suffix), "-%d.pcm", msu_track);
       strcpy((char*)file_buf, (char*)file_lfn);
@@ -156,7 +156,7 @@ int msu1_loop() {
 	 || (msu_offset >= msu_page2_start + msu_page_size))) {
 	printf("offset %08lx out of range (%08lx-%08lx, %08lx-%08lx), reload\n", msu_offset, msu_page1_start,
 	       msu_page1_start+msu_page_size-1, msu_page2_start, msu_page2_start+msu_page_size-1);
-	/* cache miss */
+	/* "cache miss" */
 	/* fill buffer */
 	set_msu_addr(0x0);
 	sd_offload_tgt=2;
diff --git a/src/spi.c b/src/spi.c
index c92bf17..2893a7a 100644
--- a/src/spi.c
+++ b/src/spi.c
@@ -81,7 +81,7 @@ uint8_t spi_txrx_byte(uint8_t data) {
   while (BITBAND(SSP_REGS->SR, SSP_RNE))
     (void) SSP_REGS->DR;
 
-  /* Transmit a single dummy byte */
+  /* Transmit a single byte */
   SSP_REGS->DR = data;
 
   /* Wait until answer has been received */