1 files changed, 5 insertions, 0 deletions
diff --git a/src/io.c b/src/io.c
index 9a3f97d..9b664d4 100644
--- a/src/io.c
+++ b/src/io.c
@@ -142,5 +142,10 @@ void writeblock(void) {
 	// fprintf(stderr, "writeblock, bufadr = $%04x, len = $%04x\n", bufadr, len);
 
 	bytes = fwrite(buf, 1, len, out_file);
+	if(bytes < 0) {
+		perror(self); /* TODO: out_filename */
+		exit(1);
+	}
+	bytes_written += bytes;
 	dpoke(buf_len_l, bytes);
 }