Woodstock Display Upgrade (a sight for sore eyes)

[markhen]

The calculator's interface to the display requires a lot of pins (8 segments and 12 digit selects (although not all 12 are required if we use some trickery)). There is only so much room under the display board where chips can be squeezed, so it has to be small packages, consequently with a small number of pins. The displays used here have a serial interface, requiring 5 pins, some (like the HPDL1414) have a parallel interface that requires lots of pins (over a dozen). Every pin on my CPU is used, none left over! Not to mention the physical constraints on the display size, it's quite a fluke these displays fit!

I've thought about a similar retrofit for Classics, but their LED interface is very special (inductors!) so making something that could plug in is questionable.