diff --git a/software/obsolete/sockbuf_test.c b/software/obsolete/sockbuf_test.c
new file mode 100644
index 0000000..d143203
--- /dev/null
+++ b/software/obsolete/sockbuf_test.c
@@ -0,0 +1,94 @@
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+static int set_int_opt(int fd, int opt, int val)
+{
+	return setsockopt(fd, SOL_SOCKET, opt, &val, sizeof(val));
+}
+
+static int get_int_opt(int fd, int opt)
+{
+	int ret, rc;
+	socklen_t optlen = sizeof(ret);
+
+	rc = getsockopt(fd, SOL_SOCKET, opt, &ret, &optlen);
+	if (rc < 0)
+		return rc;
+	return ret;
+}
+
+static int set_nonblock(int fd)
+{
+	int flags;
+	flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		return flags;
+	flags |= O_NONBLOCK;
+
+	return fcntl(fd, F_SETFL, flags);
+}
+
+static int run_test_socketpair(int tx_buf)
+{
+	int rc, sd[2];
+	uint8_t buf[1024*1024];
+
+	memset(buf, 0, sizeof(buf));
+
+	rc = socketpair(AF_UNIX, SOCK_STREAM, 0, sd);
+	if (rc < 0)
+		return rc;
+
+	/* set the lowest possible transmit socket buffer */
+	set_int_opt(sd[0], SO_SNDBUF, tx_buf);
+	set_nonblock(sd[0]);
+
+	rc = write(sd[0], buf, sizeof(buf));
+	printf("socketpair: tx_buf %7d: written %7d of %ld\n", tx_buf, rc, sizeof(buf));
+
+	close(sd[0]);
+	close(sd[1]);
+	return 0;
+}
+
+static int run_test_pipe(int tx_buf)
+{
+	int rc, sd[2];
+	uint8_t buf[1024*1024];
+
+	memset(buf, 0, sizeof(buf));
+
+	rc = pipe(sd);
+	if (rc < 0)
+		return rc;
+
+	set_nonblock(sd[1]);
+
+	rc = write(sd[1], buf, sizeof(buf));
+	printf("pipe: tx_buf %7d: written %7d of %ld\n", tx_buf, rc, sizeof(buf));
+
+	close(sd[0]);
+	close(sd[1]);
+	return 0;
+}
+
+
+
+
+int main(int argc, char **argv)
+{
+	int i;
+
+	for (i = 0; i < 20; i++) {
+		run_test_socketpair(1<<i);
+	}
+	run_test_pipe(0);
+}