Any vintage Apple buffs that can explain the ARM logo on this Macintosh Processor Upgrade Card (PowerPC 601 PowerMac, circa 1994)? I know Apple & VLSI were seed investors in ARM. Do old PowerPC chipsets have an embedded management core? https://mastodon.social/media/6DXjn70Niv-zKOw1JRQ
An earlier prototype has much the same chips, but no big ARM logo.
I think VLSI were the first ARM licensee - there could be an ARM in there, and given the label, I think there must be. Perhaps needed to setup the board for the PPC to boot.
@projectgus @EdS According to https://web.archive.org/web/20020817155956/http://docs.info.apple.com/article.html?artnum=16722 it was possible to switch between the PPC and the m68k CPU with a reboot, so there must have been some pre-boot toggle to decide which CPU to power up - can't have been both on the bus.
The MacWorld image designates the chip as "040 bus adapter and cache controller", which sounds plausible (the card seems to have brought a Mac PPC ROM, but had to talk to memory and periphereals over the 68040 CPU bus).
From Twitter comes a few clues:
Apple not the designer for these, Daystar.
A "real" PowerMac 6100 of the same era has no VLSI chips at all. https://images.esellerpro.com/2131/I/542/07/POWERMAC6100%20001.jpg …
Similar era 68K Macs have lots of VLSI chips but nothing marked ARM.