The June Scientific American 2-page "Working Knowledge" article is on E-Ink ebook readers. Only the 1st paragraph is on line
here. The print article's title is "Library to Go" (rather than "Inside the Kindle E-Book Reader") and it features both the Kindle and the PRS-505. In fact, the generic reader schematic seems to be a PRS-505, not a Kindle. If you see the June SciAm on a newsstand it would be worth a look (pages 108-109), but I don't think it alone is worth buying the magazine for.
I subscribe to the paper magazine, but I see that the electronic version is in PDF. Probably the best choice for such a magazine, but not suitable for the current generation of E-Ink readers.