In my previous article, Finally: bringing Internet to my Colour Classic, I mentioned I have a motherboard from a Macintosh LC 580 in my possession, and wrote that it
…fits perfectly in a Colour Classic and makes for a nice overall upgrade (it has a Motorola 68LC040 at 33MHz CPU versus the original 68030 at 16MHz of the Colour Classic, and the RAM can be expanded to a maximum of 52 MB instead of the meagre 10 MB of the original motherboard).
A few readers have written to me, both via comments and private emails, that I got the reference wrong, that I must be referring to a Macintosh LC 575 motherboard, because the motherboard from an LC 580 wouldn’t fit in a Colour Classic without major modifications.
I want to thank everyone for the feedback. You are indeed correct — it’s a Macintosh LC 575 motherboard. And that quote should actually read:
Luckily, years ago I also acquired the motherboard from a Macintosh LC 575, which fits perfectly in a Colour Classic and makes for a nice overall upgrade (it has a Motorola 68LC040 at 33MHz CPU versus the original 68030 at 16MHz of the Colour Classic, and the RAM can be expanded to a maximum of 68 MB instead of the meagre 10 MB of the original motherboard).
Why I wrote LC 580
The person who gave me that motherboard 14 years ago didn’t remember whether it was from an LC 575 or 580, and I wrote ‘LC 580’ because, having never seen the motherboard of an LC 580 before, I relied on the information provided by Mactracker. The application lists the Macintosh LC 575 as having two ADB ports, and the LC 580 as having one. Given that, on paper, the technical specifications of the two Macs are rather similar, I used the difference in ADB ports to identify the motherboard in my possession — it has one ADB port only, so I deduced it was from an LC 580.
It turns out that Mactracker is wrong in this instance. The Macintosh LC 575, too, has just one ADB port, as correctly reported by Apple History, EveryMac.com and, of course, by Apple itself. I usually rely on Mactracker to quickly check up technical specifications for Apple products, because it’s usually a complete and reliable resource. But this little error threw me off track.
Motherboards: a visual comparison
Finally, in case other people get confused, here are a couple of pictures that should further clarify things visually: