[Doctor_Fegg]

Yep. The Amstrad CPC was an effective 3.3MHz. Most 8-bit machines of the early 80s had reasonably comparable CPU performance: the real speed differentiators were the graphics hardware (Spectrum fast because you had so few colour bytes to write, CPC slow - until you learned how to scroll with the CRTC) and, if you used it, the efficiency of the BASIC/firmware.

There was a 16MHz Z80: Amstrad briefly built a machine on it in the 1990s (the PcW16).

[opencl]

TI still sells 15Mhz Z80s in their TI84 graphing calculators.

[mavhc]

And still charges what they cost in the 80s

[vanderZwan]

I'm kind of wondering why there isn't an open hardware calculator yet. Given the mark-up most of these brands have, it might actually be viable.

[colejohnson66]

The ACT and SAT require certified calculators

[vanderZwan]

Well, I imagine we could get citizen funding for that.

EDIT: Oh, the certificate is with the product? Well, there might be some smaller players who currently can't compete with TI who could handle the production side.

Hardware-wise it should definitely be easy enough to create a cheaper calculator just as capable of meeting the requirements, no?

[colejohnson66]

Why do people still buy the TI-84? I used a TI NSpire when I was in school and it cost about the same