Sharp PC-E500 Turbo mode?

[Bushcat]

Do you mean a hardware clock upgrade? That requires two components: swap out the existing Ceralock for a 4.8 MHz Ceralock; replace the existing 180k resistor with a 68k resistor. There's a diagram somewhere showing how to put the Ceralock in parallel with the existing one, using a small switch to flip between them.

If there's "turbo" setting or software, then I'm barking up the wrong tree so ignore me :-)