In 1978, Parker Brothers released Merlin — a red, phone-shaped electronic game with eleven glowing buttons. In Britain it came from Palitoy. Millions of kids wore out its batteries, and two of them were sisters: Ana and Beth — my wife's mother and her aunt.
Of the six games Merlin could play, theirs was Magic Square. Press a button and a little cluster of lights flips — corners flip their corner block, edges flip a whole row or column, the center flips a plus. The goal: light the outer ring, leave the center dark. Simple to describe, maddening to put down. They passed that red machine back and forth for hours, and nearly fifty years later they still talked about it.
The originals are collectors' items now, and the sisters' own Merlin is long gone. So I rebuilt their puzzle as an iPhone app — and tried to be faithful about the details that make the memory: the authentic flip rules, the warm red glow, the buzzy beeps (synthesized live as square waves, the way the original's little speaker made them), and the victory lap the lights run when the square finally completes.
It's called Sisters' Magic Square, and there's a dedication to Ana and Beth tucked inside. It's free — no ads, no accounts, no tracking. There's an optional tip jar that unlocks nothing; the whole game is yours either way.
If you had a Merlin — or sat next to someone who wouldn't hand it over — this is for you too. Light the ring. Leave the center dark. Enjoy the glow.
Sisters' Magic Square is an independent tribute, not affiliated with, sponsored, or endorsed by Hasbro. Merlin is a trademark of its respective owner. The puzzle mechanic itself is a bit of beautiful public mathematics.