The 486 Macintosh was actually sold.

I just discovered that the "Star Trek" Macintosh with an Intel 80486 CPU made it past prototype stage and was sold for 14 months as the Macintosh 6100/66. There are Macintosh Classic x86 machines in the wild. The PPC motherboard ran System 7 and had an on board card with a 486, dedicated RAM slots (for regular Mac 6100 SIMMS), SVGA output, SoundBlaster compatible sound card (by Creative Labs), and a PC joystick port. Although it would use the Mainboard RAM if none was present on the card. This made it an IBM-PC compatible, or as the badge on the front said "DOS Compatible". The card and the motherboard could run their operating systems simultaneously, on two monitors even. On a low-level, the Mac OS had full access to all the hardware on the card but apparently the card was unaware of the Mac host. 'Star Trek Mac' games designed to use any or all hardware on the x86 card were completely possible. Considering that this star trek mac was not the only x86 option ever created for the platform (just the only official one), x86 game for classic mac seem more likely. At least one game developer should have considered using at least one feature of the card even if it wasn't the 486.

The card itself is compatible with 7.5, 7.5.1, 7.5.3, 7.5.5, 7.6.1, 7.6, 8.5, 8.0, 8.1, 8.6

It is kind of strange, Mac devotees seem to want to erase this Mac from history going so far as removing the x86 card and breaking off the "DOS Compatible" part of the badge.

Oh, in case UVL editors haven't heard, Apple is changing architectures *again*. They will be switching to a custom 64-bit ARM SOC similar to (or exactly the same as) the CPUs used in their mobile devices.