alt Hacker NewsThe TI-84+ uses a TI REF 84PLUSB (or variant) ASIC that has a Z80-compatible core in it, not a Zilog Z80, and, as you say, definitely not a DIP40 part.
See the ASIC here, in what looks to me like a QFP-144 package: https://guide-images.cdn.ifixit.com/igi/e25cVO2avPxiMoXl.hug...
The CE also uses an ASIC, but with an eZ80 core instead.
Thank you! I had a job coding Z80 assembly "back in the day" and grew to love its instruction set so I'm not surprised there is legacy and value to keep stuffing wee Z80ish cores into modern devices.
I also found this gem just now: http://datamath.org/Album_Graph.htm