The processor in the TI-84 is a custom part built around an eZ80 IP core. There are faster 8-bit CPUs available off the shelf, though. Hell, Silicon Labs makes

The processor in the TI-84 is a custom part built around an eZ80 IP core. There are faster 8-bit CPUs available off the shelf, though. Hell, Silicon Labs makes some 8051 microprocessors that'll run at up to 100 MHz.