Japi Base v0.5 — switchable CPU clock (260 / 324 / 390 MHz)

What's new

A runtime-switchable CPU clock with an automatic safety net. Japi Base can now run at three CPU speeds, each with its own core voltage, while the 1024x768@60 picture stays exactly the same -- the VGA program switches cycles-per-pixel so the dot clock stays ~65 MHz on every tier:

• 260 MHz @ 1.15 V -- the safe floor
• 324 MHz @ 1.20 V -- the default
• 390 MHz @ 1.30 V -- an opt-in up-size (lucky-silicon bonus; not every board can hold it)

The chosen speed is stored in flash and applied on a clean reboot. If a board cannot hold a speed the hardware watchdog catches it and steps down one tier on its own (390 to 324, 324 to 260) -- a board that cannot do the high gear is never bricked and never needs a re-flash.

Try it on the CPU Benchmark page: Shift+T up-sizes, t down-sizes. The benchmark times a fixed workload with a clock-independent timer so you can watch the throughput scale with the clock while the checksum stays identical, which proves the math is still correct at speed.

Install

Hold BOOTSEL while plugging in the Pico 2, then copy japi_base_v0.5.uf2 onto the RP2350 drive.

Full changelog: v0.4...v0.5