classic mac

endangered-classic-mac-plastic-color-returns-as-3d-printer-filament

Endangered classic Mac plastic color returns as 3D-printer filament

3d printers, 3D printing, Apple, Apple IIgs, classic mac, computer collecting, Joe Strosnider, Macintosh, Macintosh Platinum, Macintosh SE, Macs, retrocomputing, retrotech, Tech, Vintage computing / /

On Tuesday, classic computer collector Joe Strosnider announced the availability of a new 3D-printer filament that replicates the iconic “Platinum” color scheme used in classic Macintosh computers from the late 1980s through the 1990s. The PLA filament (PLA is short for polylactic acid) allows hobbyists to 3D-print nostalgic novelties, replacement parts, and accessories that match the original color of vintage Apple computers.

Hobbyists commonly feed this type of filament into commercial desktop 3D printers, which heat the plastic and extrude it in a computer-controlled way to fabricate new plastic parts.

The Platinum color, which Apple used in its desktop and portable computer lines starting with the Apple IIgs in 1986, has become synonymous with a distinctive era of classic Macintosh aesthetic. Over time, original Macintosh plastics have become brittle and discolored with age, so matching the “original” color can be a somewhat challenging and subjective experience.

A close-up of

A close-up of “Retro Platinum” PLA filament by Polar Filament. Credit: Polar Filament

Strosnider, who runs a website about his extensive vintage computer collection in Ohio, worked for years to color-match the distinctive beige-gray hue of the Macintosh Platinum scheme, resulting in a spool of hobby-ready plastic by Polar Filament and priced at $21.99 per kilogram.

According to a forum post, Strosnider paid approximately $900 to develop the color and purchase an initial 25-kilogram supply of the filament. Rather than keeping the formulation proprietary, he arranged for Polar Filament to make the color publicly available.

“I paid them a fee to color match the speaker box from inside my Mac Color Classic,” Strosnider wrote in a Tinkerdifferent forum post on Tuesday. “In exchange, I asked them to release the color to the public so anyone can use it.”

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the-upside-down-capacitor-in-mid-‘90s-macs,-proven-and-documented-by-hobbyists

The upside-down capacitor in mid-‘90s Macs, proven and documented by hobbyists

Apple, capacitors, classic mac, Mac LC III, Macintosh, restoration, Tech, vintage computers, Vintage computing / /

Brown notes that the predecessor Mac LC and LC II had the correct connections, as did the LC 475, which uses the same power supply scheme. This makes him “confident that Apple made a boo-boo on the LC III,” or “basically the hardware equivalent of a copy/paste error when you’re writing code.”

Making sure rehabbers don’t make the same mistake

Why was this not noticed earlier, other than a couple forum threads seen by dedicated board rehabbers? There are a few reasons. For one thing, the rail was only used for a serial port or certain expansion card needs, so a capacitor failure, or out-of-spec power output, may not have been noticed. The other bit is that the original capacitor was rated for 16V, so even with -5V across it, it might not have failed, at least while it was relatively fresh. And it would not have failed in quite so spectacular a fashion as to generate stories and myths.

As to whether Apple knew about this but decided against acting on a somewhat obscure fault, one that might never cause real problems? By all means, let us know if you worked at Apple during that time and can clue us in. Ars has emailed Apple with this tremendously relevant question, the day before Thanksgiving, and will update this post with any comment.

By posting his analysis, Brown hopes to provide anyone else re-capping one of these devices with a bright, reflective warning sign to ignore Apple’s markings and install C22 the electrically correct way. Brown, reached by email, said that he heard from another hobbyist that the reverse voltage “would explain why the replacement cap” they installed “blew up.” Some restoration types, like Retro Viator, noticed the problem and fixed it pre-detonation.

Modern rehabbers tend to use tantalum capacitors to replace the fluid-filled kind that probably damaged the board they’re working on. Tantalum tends to react more violently to too much or reverse voltage, Brown wrote me.

Should C22 or other faulty capacitors destroy your LC III board entirely, Brown notes that 68kMLA member max1zzz has made a reverse-engineered full logic board schematic.

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