On these pages, you'll find support for various vintage PC-related topics, in the form of FAQs and software. You'll also find some obscure information that may hopefully help you in whatever it is you're trying to accomplish.
Really old mailing lists
The Google Usenet Archive
The Internet Wayback Machine
C compiler discussion, from a PCBoard in 1987
NUMbers CD-ROMs, archived site of a 1993-1998 pirate software vendor
Big Blue Disk, a monthly disk magazine published by Softdisk starting in 1986
If you are looking for the companion disk/diskette from the Sargent & Shoemaker book, "The Personal Computer From The Inside Out", look no further.
Here are some disorganized notes on how to get BSI WaveStation version 3 running again when install media is unavailable (i.e. after a crash).
Computers of yesterday are like the "big iron" automobiles of the old era. They were simpler in design, and built to take a beating. While a fan-less 1GHz CPU will last for about 10 seconds, I can replace chips on a Commodore 64 mainboard WHILE IT'S RUNNING. The average laptop computer won't survive a fall of more than 3 inches, but I can drop my Tandy Model 102 from a height of six feet and it emerges without a scratch. The systems may be less powerful, but they are far more resilient. This is a notion that has been lost in the age of the PC as a ubiquitous, non-optional consumer appliance.