Sean Malseed's "Mac Minus" Imagines a World in Which Miniature Apple Macintoshes Run Acorn's RISC OS

Vintage computing enthusiast Sean Malseed has put a 3D printer to work creating a "Mac Minus" — a miniaturized all-in-one PC inspired by Apple's classic Macintosh Plus and with a real 5" cathode-ray tube (CRT) display.

"The Mac Plus is one of the most iconic computers of the 1980s," Malseed says of the original device which served as inspiration for his project, "but it's just so big and unwieldy. So, [I decided] to miniaturize this behemoth — including a fully-functional 5" glass CRT [display]."

The original Macintosh Plus was released in 1986 as the third entry in Apple's hugely successful Macintosh line-up, offering twice the RAM of its predecessor and the ability to install up to 4MB. Like all Macs of its era, its display was a 9" monochrome cathode-ray tube (CRT) — and while compact by the standards of modern flat-screen displays, even a 9" CRT is a hefty beast.

Malseed's take on the concept builds on a design released on Thingiverse back in September 2022 for a "Mac Minus": a 3D-printable shell that mimics the overall shape of the Macintosh Plus but on a smaller scale, replacing the original 9" CRT with a 5" version. "In my experience the TV [displays] have too much variance on their implosion bands and analog boards for me to make something work for everything," pseudonymous designer "Indiana_Jones" wrote at the time, "beyond letting people design their own internals."

Like the original Mac Minus design, Malseed's version uses a real 5" CRT salvaged from a discarded black-and-white TV set. "I think the glass CRT is one of the most defining iconic features of the classic Mac," he explains. The display is drive by a Raspberry Pi single-board computer — the original Model B, a 2012 vintage that has only two USB 2.0 ports and includes the RCA jack for composite video dropped from later models.

Where Malseed's project differs from most Mac replicas, though, is in ditching the idea of emulating Apple's original hardware. Instead, Malseed's Mac Minus runs RISC OS, an operating system originally designed by Acorn Computers for what was known at the time as the Acorn RISC Machine processor — and which today exists as Arm, the architecture behind the Raspberry Pi range.

Malseed's full video is available embedded above and on the Action Retro YouTube channel.