I fetched the Radio Shack Service Manual for the Model 100 (26-3801/3802) and the Tandy 102 Technical Reference Manual (26-252) and both discuss the LCD display timing details along with a driver schematic for each.
(All images snipped from PDF copies of the manuals listed above, both of which I grabbed from Club 100.)
So, let's compare Model 100 Fig. 4-14:
and Fig. 4-15:
with the Model 102 Figure 2-10:
and Figure 2-11:
In general, the LCD connector pin-outs look the same, as do the timing and signal descriptions. There are a few differences in how those pins are driven by the discrete components, but this might just be an artefact of how the schematics were drawn.
They look very similar, electronically, and appear to be pin-compatible. I'd want to stare hard at the driver circuitry details to make sure I understood the differences.
I think the differences in the driver circuits are not significant:
- Either the Model 102 has an additional buffer between Y7 and pin 18 or the buffer is drawn in one case and not the other. But those should be the same, electrically.
- Pin 19 looks identical to my eyes.
- Pin 4 (the circuit for controlling the contrast it looks like) look equivalent to me, even if the part numbers have changed. The voltage divider resistors are the same values, anyway. There are missing capacitors (decouplers?) in the 102 schematic, but maybe those were deemed unnecessary (or C16 obviates them).
Maybe someone else here could tell us if any of that raises some red flags.