Truchet Tiles in PETSCII: Commodore 64

8-Bit Show and Tell host Robin returns with a deep dive into Truchet tiles, drawing inspiration from the classic 10 PRINT book. In this video he digs into 1704 designs by Father Sebastien Truchet, discovering that the Commodore 64’s PETSCII character set already includes the original Truchet tiles. Using a single diagonal tile rotated in four directions, he recreates all 30 patterns from Truchet’s memoir, shifting from historic engraved designs to hypnotic PETSCII art. He shows how the built-in diagonals and character codes can generate full-screen patterns and promises a future code walk-through to share his 6510 assembly secrets.

Robin also notes some quirky details about the 1700s alphabet: certain letters like J, K and W were missing, so he substitutes the ampersand (&) for pattern 24 and includes six bonus patterns labelled 1–6. He celebrates the imperfect pixel ratios of the C64, arguing that the slightly off-centre diagonals give the patterns "imperfect pixels, perfect charm" and emphasises how history and "nerdy fun" come together. Viewers are invited to download the program’s .D64 disk image, explore the patterns themselves and look forward to the promised assembly deep dive. Comments appear to be disabled on this video, but reactions on retro-computing blogs praise the blend of art, geometry and programming.