diff --git a/README.md b/README.md
index d9367e2f..b1a55908 100644
--- a/README.md
+++ b/README.md
@@ -2,12 +2,16 @@
 
 The CubeSat Simulator https://github.com/alanbjohnston/CubeSatSim/wiki is a low cost satellite emulator that run on solar panels and batteries, transmits UHF radio telemetry, has a 3D printed frame, and can be extended by additional sensors and modules.  This project is sponsored by the not-for-profit [Radio Amateur Satellite Corporation, AMSAT®](https://amsat.org).
 
-See the Wiki Software Install page for more details: https://github.com/alanbjohnston/CubeSatSim/wiki/Software-Install. To build and run the software on a Raspberry Pi 3B, 3B+, or Pi Zero W:
+This is not the latest version of the CubeSatSim - find the master branch.
+
+See the Wiki Software Install page for more details: https://github.com/alanbjohnston/CubeSatSim/wiki/vB2-Software-Install. To build and run the software on a Raspberry Pi 3B, 3B+, or Pi Zero W:
 
 `git clone http://github.com/alanbjohnston/CubeSatSim.git`
 
 `cd CubeSatSim`
 
+`git checkout aprs-digitaltxrx`
+
 Edit the afsk/main.c file to set your amateur radio callsign, then 
 
 `make rebuild`
@@ -32,6 +36,6 @@ This repository contains:
  - python - Python code for reading I2C sensors for current and temperature
  - spreadsheet - Spreadsheets for decoding and analyzing the Simulator telemetry (see https://github.com/alanbjohnston/CubeSatSim/wiki/Decoding-Telemetry for details)
  - wav - Wave audio files of CW or AFSK telemetry for listening or transmitting usng a CubeSat Simulator Lite
- - demo.sh - a shell script to run the Simulator on boot using systemd (see https://github.com/alanbjohnston/CubeSatSim/wiki/Software-Install#autoboot-configuration for how to configure the Pi)
+ - demo.sh - a shell script to run the Simulator on boot using systemd (see https://github.com/alanbjohnston/CubeSatSim/wiki/vB2-Software-Install#autoboot-configuration for how to configure the Pi)
 
 See the Wiki for more details https://github.com/alanbjohnston/CubeSatSim/wiki