Reviving meowTOAST: Updates & Improvements

Do you remember meowTOAST, the CR2032 coin-cell adapter for 1/2AA battery sockets that my bro Stephen Arsenault originally came up with?

That was back in 2021, and as far as I know, it was likely the very first battery adapter ever made specifically for Macintosh computers. Several similar adapters were released by other makers afterward, but I’m quite sure Stephen’s design was the original.

Stephen’s earliest revision is archived here: https://github.com/Stephen-Arsenault/meowTOAST

He updated the design twice after that. The first CR2032 snap he used resembled a cat’s face, which inspired the name “Meow”—a clever and charming touch.

Later, Drake created a fun illustration based on Stephen’s PCB and named it “DONT4GET”. I really loved both the artwork and his naming sense. I had originally planned to sell their designs unchanged, but various SMC projects kept me busy and the idea stayed on hold.

This time, I’ve decided to re-release the design—mostly unchanged—while adding a few improvements of my own.

Improvement 1: Optional capacitor footprint

On the Macintosh II battery board, the electrolytic capacitor plays an important role in stabilizing the soft-power circuit that uses Apple’s PFU (Power Fail/Up) system. Noise or brief interruptions on the power-control signal can cause resets or erratic behavior, so this capacitor acts as a filter and improves reliability. Early boards typically used 1000 µF, while later revisions used 100 µF for improved stability with different power characteristics.Our updated adapter includes an optional footprint for a capacitor. Space is limited, but a 1210-size capacitor can be installed.

Improvement 2: ENIG finish

ENIG (Electroless Nickel Immersion Gold) is ideal for edge fingers: gold resists oxidation, offers stable contact resistance, reduces wear, and maintains reliability even after long storage. It also looks great and adds a premium feel. For these reasons, I’ve adopted ENIG for the battery-socket contact surfaces.

Improvement 3: Jumper pads

The board now includes two jumper locations, allowing the battery socket to be positioned farther from the logic board for easier replacement. This will be offered as an optional configuration.

Designed for both vertical and horizontal placement

A note about the original design: placing the positive and negative terminals in the center results in a vertically asymmetrical mount, which also allows the holder to be installed vertically. Our enthusiastic friend jmacz even created a custom STL holder to improve on this concept: https://www.printables.com/refresh?redirectUrl=%2Fmodel%2F1223222-meow-toast-holder

I’m excited to finally offer Stephen’s and Drake’s designs through Kero’s Mac Mods: https://en.infinityproducts.co.jp/shop-1

Stay tuned!