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+# greenctld
+
+A hamlib-compatible driver for the [Green Heron Engineering RT-21 Digital Rotor
+Controller](https://www.greenheronengineering.com/prod_documents/controllers/docs/RT-21_Manual_current.pdf).
+hamlib does not support the rotor, but this program can be used as a drop-in
+replacement for rotctld when commanding the RT-21.
+
+The RT-21 is unlike most of the other rotors hamlib supports in that it uses
+two serial ports, one for controlling azimuth and one for controlling
+elevation.  The two serial ports are passed via the ```--az-device``` and
+```--el-device``` command line arguments.
+
+The TCP network protocol is compatible with the hamlib protocol documented in
+the [rotctld(8) man
+page](http://manpages.ubuntu.com/manpages/zesty/man8/rotctld.8.html).  This
+driver only implements a subset of that protocol, which includes the subset
+that [gpredict](http://gpredict.oz9aec.net/) uses.  At [Astro
+Digital](https://astrodigital.com/), this driver has been used extensively with
+gpredict.  For debugging the network protocol, the ```--dummy``` option can be
+used to simulate a rotor without connecting to a real serial port.
+
+Like rotctld, this program does not daemonize on its own.  It also produces
+copious debugging output to stdout.
+
+### Usage
+
+ * ```--az-device <serial-port>```, the serial port to use for azimuth
+
+ * ```--el-device <serial-port>```, the serial port to use for elevation
+
+ * ```--speed <baud>```, the serial baud rate to use, defaults to 4800
+
+ * ```--timeout <seconds>```, the serial port timeout, defaults to 1.5
+
+ * ```--port <port>```, the TCP port to listen for connections on, defaults to 4533, the same as rotctld
+
+ * ```--get-pos```, to query the serial ports for the current az/el, and immediately exit.  Useful for testing the serial port configuration.
+
+ * ```--dummy```, to speak the TCP network protocol only without connecting to a serial port, useful for debugging gpredict integration.
+
+### License
+
+Copyright (c) 2017 [Astro Digital, Inc](https://astrodigital.com/)
+
+Released under the terms of the Simplified BSD License; see the [LICENSE](LICENSE) file for details.
+
+### Author
+
+Michael Toren &lt;mct@toren.net&gt;
diff --git a/README.md b/README.md
index cb2f778..8eb468e 100644
--- a/README.md
+++ b/README.md
@@ -1,49 +1,22 @@
 # greenctld
+Controller software for Green Heron.
 
-A hamlib-compatible driver for the [Green Heron Engineering RT-21 Digital Rotor
-Controller](https://www.greenheronengineering.com/prod_documents/controllers/docs/RT-21_Manual_current.pdf).
-hamlib does not support the rotor, but this program can be used as a drop-in
-replacement for rotctld when commanding the RT-21.
 
-The RT-21 is unlike most of the other rotors hamlib supports in that it uses
-two serial ports, one for controlling azimuth and one for controlling
-elevation.  The two serial ports are passed via the ```--az-device``` and
-```--el-device``` command line arguments.
+# Upstream
+Port from Python2 to Python3 of mct's greenctld.
 
-The TCP network protocol is compatible with the hamlib protocol documented in
-the [rotctld(8) man
-page](http://manpages.ubuntu.com/manpages/zesty/man8/rotctld.8.html).  This
-driver only implements a subset of that protocol, which includes the subset
-that [gpredict](http://gpredict.oz9aec.net/) uses.  At [Astro
-Digital](https://astrodigital.com/), this driver has been used extensively with
-gpredict.  For debugging the network protocol, the ```--dummy``` option can be
-used to simulate a rotor without connecting to a real serial port.
+* https://github.com/mct/greenctld
 
-Like rotctld, this program does not daemonize on its own.  It also produces
-copious debugging output to stdout.
+Copyright (c) 2017, Astro Digital, Inc.
 
-### Usage
 
- * ```--az-device <serial-port>```, the serial port to use for azimuth
+# License / Copyright
+Same as upstream, permissive license
 
- * ```--el-device <serial-port>```, the serial port to use for elevation
+Source:
 
- * ```--speed <baud>```, the serial baud rate to use, defaults to 4800
+* https://spacecruft.org/spacecruft/greenctld
 
- * ```--timeout <seconds>```, the serial port timeout, defaults to 1.5
 
- * ```--port <port>```, the TCP port to listen for connections on, defaults to 4533, the same as rotctld
+Copyright (C) 2022 Jeff Moe.
 
- * ```--get-pos```, to query the serial ports for the current az/el, and immediately exit.  Useful for testing the serial port configuration.
-
- * ```--dummy```, to speak the TCP network protocol only without connecting to a serial port, useful for debugging gpredict integration.
-
-### License
-
-Copyright (c) 2017 [Astro Digital, Inc](https://astrodigital.com/)
-
-Released under the terms of the Simplified BSD License; see the [LICENSE](LICENSE) file for details.
-
-### Author
-
-Michael Toren &lt;mct@toren.net&gt;