B7971 SmartSocket Brightness Control

[Robert Armstrong]

  I've finally accumulated a set of six B7971 tubes - I've had 5 that I've been carrying around with me since I bought them from PolyPaks in the 1970s, and I recently got two more at a price I can live with.  That gives me six and a spare :-)

  I'm planning on building a clock using six of the 7971 SmartSockets (the TES version, if it matters) and I'll hook them up to a serial port on one of my Linux machines as the "brains".

  Looking at the protocol for the SmartSockets, though, it doesn't appear that there's any way to control the brightness.  That seems odd - they have so many other features, and it seems like it'd be easy enough to do in firmware with PWM.  Am I missing something obvious, or is this feature really not implemented?  Has anybody extended the PIC firmware to add brightness control?

Thanks,

Bob