diff --git a/kernel/README.md b/kernel/README.md
index 6d56d7d..ebd48a7 100644
--- a/kernel/README.md
+++ b/kernel/README.md
@@ -43,6 +43,24 @@ actually capture and decode C64 traffic, use **`launch.sh`**, which installs the
 frontend, loads the matching module, runs `iecpoc`, and unloads on exit — see the
 [top-level README](../README.md#running-the-frontend-on-the-pi).
 
+### Frontend output modes
+
+`iecpoc` has three output modes, selected by flags passed after `--` to `launch.sh`
+(or directly on the command line when running `iecpoc` standalone):
+
+| Mode | Flag | Output |
+|---|---|---|
+| Plain text (default) | *(none)* | Received characters only; LISTEN/UNLISTEN print a divider; CR/LF become real newlines |
+| Debug / annotated trace | `--debug` | Full `[CMD]` / `[DATA]` / `[ATN]` / `[IDLE]` tag-per-record trace |
+| Raw hex | `--raw` | Bare uppercase hex bytes of command and data records, no annotations |
+
+```bash
+sudo ./launch.sh                        # plain text — what the C64 is printing
+sudo ./launch.sh -- --debug             # full annotated trace
+sudo ./launch.sh -- --raw               # bare hex stream
+sudo ./launch.sh -- --logfile trace.txt # also write output to a file
+```
+
 You don't pick the file yourself: the script reads `uname -r`, then scans
 `modules/` (and a few fallback locations) and selects the `.ko` whose **vermagic**
 matches the running kernel. Matching is by vermagic rather than filename because