diff --git a/spool/Makefile b/spool/Makefile
new file mode 100644
index 0000000..f3a00af
--- /dev/null
+++ b/spool/Makefile
@@ -0,0 +1,25 @@
+#
+# spool/Makefile - Build the job spooler
+#
+# Written 2008, 2009, 2012 by Werner Almesberger
+# Copyright 2008, 2009, 2012 Werner Almesberger
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+
+
+MAIN = spool
+OBJS = spool.o serial.o
+
+CFLAGS = -Wall -Wshadow
+
+all:		$(MAIN)
+
+$(MAIN):	$(OBJS)
+		$(CC) $(LDFLAGS) -o $(MAIN) $(OBJS)
+
+clean:
+		rm -f $(OBJS)
diff --git a/spool/serial.c b/spool/serial.c
new file mode 100644
index 0000000..b3392b1
--- /dev/null
+++ b/spool/serial.c
@@ -0,0 +1,100 @@
+/*
+ * serial.c - Send data to a Modela MDX-15/20
+ *
+ * Written 2009 by Werner Almesberger
+ * Copyright 2009 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <sys/types.h>
+
+#include "serial.h"
+
+
+static int tty;
+static struct termios old;
+
+
+static void reset_tty(void)
+{
+	if (tty >= 0)
+		if (tcsetattr(tty, TCSADRAIN, &old) < 0)
+			perror("tcsetattr");
+}
+
+
+void serial_open(const char *name)
+{
+	struct termios new;
+
+
+	tty = open(name, O_WRONLY | O_NOCTTY);
+	if (tty < 0) {
+		perror(name);
+		exit(1);
+	}
+
+	if (tcgetattr(tty, &old) < 0) {
+		perror("tcgetattr");
+		exit(1);
+	}
+	atexit(reset_tty);
+
+	new = old;
+	cfmakeraw(&new);
+	cfsetospeed(&new, B9600);
+	new.c_iflag |= IXON;
+	new.c_cflag |= CLOCAL | CRTSCTS;
+	new.c_lflag &= ~ECHO;
+	if (tcsetattr(tty, TCSAFLUSH, &new) < 0) {
+		perror("tcsetattr");
+		exit(1);
+	}
+}
+
+
+void serial_close(void)
+{
+	reset_tty();
+	(void) close(tty);
+	tty = -1;
+}
+
+
+void serial_printf(const char *fmt, ...)
+{
+	char buf[10000]; /* more than enough :) */
+	va_list ap;
+	int len;
+	ssize_t wrote;
+
+	va_start(ap, fmt);
+	len = vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+	if (len >= sizeof(buf)-1) {
+		fprintf(stderr, "buffer too small\n");
+		exit(1);
+	}
+	wrote = write(tty, buf, strlen(buf));
+	if (wrote < 0) {
+		perror("write");
+		exit(1);
+	}
+	if (wrote != len) {
+		fprintf(stderr, "short write: %d < %d\n",
+		    (int) wrote, (int) len);
+		exit(1);
+	}
+}
diff --git a/spool/serial.h b/spool/serial.h
new file mode 100644
index 0000000..b65e826
--- /dev/null
+++ b/spool/serial.h
@@ -0,0 +1,21 @@
+/*
+ * serial.h - Send data to a Modela MDX-15/20
+ *
+ * Written 2009 by Werner Almesberger
+ * Copyright 2009 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#ifndef SERIAL_H
+#define SERIAL_H
+
+void serial_open(const char *name);
+void serial_close(void);
+void serial_printf(const char *fmt, ...);
+
+#endif /* !SERIAL_H */
diff --git a/spool/spool.c b/spool/spool.c
new file mode 100644
index 0000000..0887f74
--- /dev/null
+++ b/spool/spool.c
@@ -0,0 +1,65 @@
+/*
+ * spool.c - Send a file to a Roland MDX series CNC mill
+ *
+ * Written 2009, 2010, 2012 by Werner Almesberger
+ * Copyright 2009, 2010, 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "serial.h"
+
+
+#define	DEFAULT_PORT	"/dev/ttyS0"
+#define BUF_SIZE	8192
+
+
+static void usage(const char *name)
+{
+	fprintf(stderr, "usage: %s [file]\n", name);
+	exit(1);
+}
+
+
+int main(int argc, const char **argv)
+{
+	FILE *file;
+	char buf[BUF_SIZE+1];
+	size_t n;
+	char *port;
+
+	switch (argc) {
+	case 1:
+		file = stdin;
+		break;
+	case 2:
+		file = fopen(argv[1], "r");
+		if (!file) {
+			perror(argv[1]);
+			exit(1);
+		}
+		break;
+	default:
+		usage(*argv);
+	}
+	port = getenv("PORT");
+	serial_open(port ? port : DEFAULT_PORT);
+	while (1) {
+		n = fread(buf, 1, BUF_SIZE, file);
+		if (!n)
+			break;
+		buf[n] = 0;
+		serial_printf("%s", buf);
+	}
+sleep(3600);
+	serial_close();
+	return 0;
+}