diff --git a/exercises/09_GPS_Time/src/main.cpp b/exercises/09_GPS_Time/src/main.cpp
index 02d3f39..c8fd2a7 100644
--- a/exercises/09_GPS_Time/src/main.cpp
+++ b/exercises/09_GPS_Time/src/main.cpp
@@ -833,11 +833,12 @@ static void gpsLogClear() {
   file.close();
   Serial.printf("Cleared %s\r\n", kGpsLogPath);
 }
-
+// Process a command received on the serial console.
 static void processSerialCommand(const char* line) {
   if (!line || line[0] == '\0') {
     return;
   }
+  // Echo the command back to the console for clarity and posterity.
   Serial.printf("-->%s\r\n", line);
   if (strcasecmp(line, "help") == 0) {
     showGpsLogHelp();
@@ -1148,6 +1149,9 @@ void setup() {
     logf("PMU init failed");
   }
 
+  // SPI Flash File System ("SPIFFS") is used for logging GPS diagnostics,
+  // which may be helpful for analyzing GPS behavior in different 
+  //environments and over time.
   g_spiffsReady = SPIFFS.begin(true);
   if (!g_spiffsReady) {
     logf("SPIFFS mount failed");
@@ -1164,12 +1168,14 @@ void setup() {
     }
   }
 
+  // Initialize the OLED display and show a boot message with build info.
   Wire.begin(OLED_SDA, OLED_SCL);
   g_oled.setI2CAddress(OLED_ADDR << 1);
   g_oled.begin();
   String buildStamp = buildStampShort();
   oledShowLines("09_GPS_Time", buildStamp.c_str(), "Booting...");
-
+  // The GPS startup probe may take a while, 
+  //especially for a cold start. Log some
   SdWatcherConfig sdCfg{};
   if (!g_sd.begin(sdCfg, nullptr)) {
     logf("SD startup manager begin() failed");