<Ahhh remember the apple II days when the entire OS source code, the tech manuals, the schematics and more were included with every one, in the box?
Those were the days!>
and even later days; I still have my copy of the IBM PC Tech Ref manual (part #1502494). It has detailed schematics for the main board and every available plug-in card, along with annotated listings of the BIOS. Too bad the tape deck control relay is no longer standard; that was fun. I hand-wired a prototype card (even that nearly bare board was detailed with the other schematics) to hold three 32 KB static RAMs; the machine had 736KB, not 640. I'm still annoyed the interrupt lines were not open-collector inputs, to allow multiple devices to sit on one line.
As for the AppleII; if you learned assembler from reading listings of that 10 pounds of code the mad Woz somehow crammed into a half-pound bag, you need therapy.