[rwmj]

The original article wants the equivalent of an open source Z80/65xx/68k, fuse settings for all the ULAs, schematics for all custom-designed chips, and open source ROM disassemblies.

1980s home computers didn't come with these, even though they had (for the time) very powerful custom graphics and sound chips (eg. Amiga [1]). Of course, some of it was reverse engineered, and some of it has been released long after the fact.

[1] https://en.wikipedia.org/wiki/Original_Chip_Set

[Someone]

1980s home computers maybe did not, but one cannot not claim Apple was locking you in in 1978. I think ftp://ftp.apple.asimov.net/pub/apple_II/documentation/misc/a2_reference_manual_alt.pdf shipped with every Apple ][. It seems to contain enough information to clone the machine (electronics diagrams, timing diagrams, ROM disassemmbly, etc.)