--- a/ater/activate.c	Mon Jun 24 18:48:36 2024 +0000
+++ b/ater/activate.c	Mon Jun 24 18:56:05 2024 +0000
@@ -71,3 +71,23 @@
 	trau_frame_from_record(init_frame, is_efr, &at->ul_frame);
 	free(init_frame);
 }
+
+void cmd_deact(int argc, char **argv)
+{
+	int nr;
+	struct ater_subslot *at;
+
+	if (argc != 2) {
+usage:		fprintf(stderr, "usage: %s 0|1|2|3\n", argv[0]);
+		return;
+	}
+	if (argv[1][0] < '0' || argv[1][0] > '3' || argv[1][1])
+		goto usage;
+	nr = argv[1][0] - '0';
+	at = &subslots[nr];
+	if (!at->is_active) {
+		fprintf(stderr, "error: subslot %d is not active\n", nr);
+		return;
+	}
+	at->is_active = false;
+}