RAE started replacing the original AR1 consoles with Cossor Compass 9000 consoles (to enable display of SSR labels) in about 1981 however the green phosphor was found to be too 'hard', there was no persistence so Cossor were prevailed upon to change to a softer orange phosphor which they did after much argument. These lasted until the Watchman replacement programme 10 years later however the Watchman radar, being fibre optic rather than copper wires, wouldn't interface with the C9000 consoles so these were sold to NATS for use at Prestwick.