[time-nuts] LED replacement screen for 53131A 53132A!!??

Mark Sims holrum at hotmail.com
Sat Jan 6 17:29:15 EST 2018

I have worked out a design for a replacement 531xx front panel that uses a micro and LCD module to emulate the VFD display.  I was going to do it when my VFD died, but just bought a couple of spare VFDs off of Ebay.

The 531xx front panel board basically has a bunch of elastomer switch contact pads and a couple VFD drivers with shift register inputs.  The output bit of the shift register chain is fed back to the motherboard for self tests.  I seem to remember that one of the VFD drivers also scans the keyboard.   

The replacement front panel micro would take in the shift register data pulses and convert the data to a format that could be drawn on the LCD display.  Of course you could use whatever type of display you like if LCDs are not to your taste.

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