0 - It has very short descriptions for each stage. There's not quite enough info to understand the "whys". Like it states that the 6501 was dropped after the threat of a lawsuit, but doesn't explain that it was because of it being pin-(and I believe signal)-compatible with the 6800, which the 6502 was not.
(month unknown) Motorola introduces its 6800 chip
The first working MC6800 chips were produced in February 1974
The references on the site consist mostly of magazines and are noticeably absent of any manufacturer's databooks/datasheets, which I'd consider looking at first before anything else.
The AL-1 came almost 2 years before Intel and TI's first microprocessors debuted and ran 10 times faster than those chips.