Fun fact: The Macintosh II (68020) had two 6502 processors on its motherboard, s... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

		kabdib on April 21, 2023 \| parent \| context \| favorite \| on: Atari 800XL Remake Fun fact: The Macintosh II (68020) had two 6502 processors on its motherboard, somewhere in the I/O system. Originally intended to do some kind of I/O acceleration, they were never used by MacOS. I heard they just ran Mandlebrot-generation test code.

rjsw on April 21, 2023 [–]

The IIfx, Quadra 900 & Quadra 950 each have two 6502 processors. They offload ADB processing (keyboard and mouse), the floppy disk and serial ports. MacOS uses all of them, NetBSD can use ADB offload.

kabdib on April 22, 2023 | [–]

Oh, cool! I thought that only A/UX had made use of them.

Consider applying for YC's Winter 2026 batch! Applications are open till Nov 10
Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact