5 Aug 2024, Special notes for New V1.3 PCB: Here is the change in the probe points and how to measure them. Please read on.

Frequency counters sold as kits are inexpensive and recommended. The links do not have any commercial causal relationship with us.
*The link I chose was the cheapest one I saw. This Chinese-made red board kit is less likely to break, so I recommend it. Please take a look at other listings and choose a cheaper and better seller.

Very small overclocking devices made in Japan developed for 68040, Spicy O'Clock! Is a silicon oscillator unit that can set the clock arbitrarily from 37.6MHz to 51.8MHz. (Actually 1/2 clock because it is doubled by the clock driver on the logic board)
This breakthrough device can generate more stable clocks than crystal oscillators and can be finely clocked in 1/100 Mhz increments during overclocking.
 
Our Instruction Manuals here
 
Here is the Spicy O'Clock bracket for Mystic and the back panel with adjustment holes. Useful for installing Spicy O'Clock.
 
Available models
 
LC475, LC575 (Mystic), LC(Performa)630, LC(Performa)588, Quadra (Centris) 650, Quadra (Centris) 800/840AV, Pioneer MPC-LX100(Mac 040clone)
 
For the above models, Spicy O'Clock! Can be used because the XC88916DW clock driver designed exclusively for 68040 generates twice the clock. In addition to the above (we have not verified), any model using the XC(MC)88916DW can be used.

Wiring diagrams here , for LC475, LC575(Mystic), Quadra650(Centris650), Quadra800Options