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> Bzzt! Wrong! Thanks for playing...

Tsk. Are kids still saying that these days?

This added a BUNCH of (unnecessary) complexity to the hardware design, causing the PCBs to employ radical (at the time) trace width and trace spacing specs, so that up to THREE traces could be routed BETWEEN .100" spaced IC pins (!!!)

That turns out to be a false rumor:

For a long time I believed the fineline six track routing rumour. One of the rumours was the issue of broken tracks due to such small traces. Even with a conservative annular ring (land) on each integrated circuit pin of 45 thou, with six tracks between the legs of a 2.54mm DIP chip, this would mean tracking of about 3 thou with 3 thou spacing (which is fineline). For 1980, that would be exceptionally impressive, especially for a board that is 39cm x 24cm in size where a linear error of up to 5 thou can occur. As it turns out, after studying the Apple III logic board, its clearly the most densely routed PCB Apple had made to date. Although the layout would be considered a high density route, it certainly is not fineline. After a thorough inspection, I could not locate any more than a mere single track between the legs of an integrated circuit, even then it resembled eight thou in width with approx five thou clearance spacing.

The causes are debatable:

Although the temperature was higher inside the Apple III than any other Apple, I still cannot see how these integrated circuits could possible work loose if they had been seated correctly the first time. To remove themselves using thermal cycling would take years, as the thermal matching between the integrated circuit's pin material, and the material of the IC sockets (both formed tin-plated) are almost identical. Considering this, I strongly suspect the initial assembly process for automatic integrated circuit insertion could be the main contributor to this problem, and not heat, as is commonly speculated.

Yes, indeed.

Schematics, theory of operation, and a fully commented ROM listing. The original IBM PC had the same info available in a manual that could be purchased separately.

Apple didn't make chips before PA Semi;

Except for chips like this: http://www.applelogic.org/file.... Late Apple ][ models, Lisa, Newton, every Apple printer since the Imagewriter,, every Mac, every iPhone, and most if not all iPods have included one or more chips designed by Apple, carrying the Apple logo, unavailable to anyone else, and usually very poorly documented (if at all.) One could also argue that the 680x0 and PPC versions that Apple commissioned for exclusive use in Macs amounted to them acting like a fabless CPU maker (e.g. like PA Semi) so if you meant "CPU" instead of "chip"

There were CPU cards for the Apple ][, but these were complete computers on a card that simply allowed use of the Apple ][ I/O.

Most of these were just a CPU (usually a Z80) and the minimal logic necessary to take over from the 6502 on the motherboard. A relatively small handful of cards included their own RAM; it was far cheaper to use what was already in the computer.

The only Apple II expansion card that comes to mind that really was a complete computer on a card was the Applied Engineering PC Transporter, which had an 8088-compatible CPU, up to 768K RAM, an MFM floppy controller, CGA-compatible graphics that could also drive an analog RGB monitor (commonly used with the IIGS), and most of the other bits that would make up a complete PC/XT-compatible computer. More recently, a Carte Blanche could be configured as a nearly standalone computer, running in an Apple II or on a board that provides Apple II expansion slots.