I'm curious about how the early handheld video games from the 70's and 80's worked. You know, those small games with a LCD display with "fixed elements" meaning it was hard wired for one (or a small number of) specific games(s). For instance,
Specifically, what type of micro controllers did these games use? As I recall, there was usually one big epoxy "blob" at the center of the board which probably controlled everything. So my question is, what was inside this blob? Was it a small standard microcontroller with a ROM running the actual game, or was it a custom CPU/controller for every design? Or maybe it wasn't even a CPU but more like a simple state machine hardwired for the game in question? I realize the answer may depend on the particular game.
Has the design/schematics for any of these games been released or is there any good books/references about how they were made? Finally, what tools were used to design microcontrollers like this? Was it based on something like VHDL/Verilog synthesis, or was it a more low-level approach with wiring the individual elements?