Author here for any questions :-) This is a change of pace from my x86 stuff, just a quick look at a 1982 Ethernet chip that unexpectedly used a second layer of polysilicon for resistors.
While trying to figure out some occasional network stalls, I looked at NetBSD's man le(4) page, which had an interesting note:
Alas, the Am7990 chip is so old that AMD has "de-archived" the production information about it; pending a search elsewhere, we don't know how to identify the revision C chip from the date codes.
Any chance this information is publicly available elsewhere?
Always fascinating writeups, Ken! Thanks :)
https://archive.org/details/bitsavers_amdAm7990A_1770429 (Rev. C)
https://www.ardent-tool.com/datasheets/AMD_Am7990.pdf (Rev. D)