Model 100 Manuals
- https://ftp.whtech.com/club100/doc/TRS80-M100-User-Guide.pdf
- https://ftp.whtech.com/club100/doc/m100qr.pdf
- https://ftp.whtech.com/club100/doc/m100ServiceManual.pdf
- https://archive.org/details/TandyM100ServiceManual (mostly higher quality scan, but the schematics are still blurry)
- https://ftp.whtech.com/club100/doc/m100TechReference.pdf
- https://archive.org/details/Model100RomFunctions/
- https://archive.org/details/Model_100_Basic_Language_Lab_1983_Tandy/
- https://archive.org/details/ProgrammingTipsPeeksAndPokesForTheTandyPortableComputers/
- https://archive.org/details/HiddenPowersOfTheTrs80Model100
- https://archive.org/details/InsideTheTrs80Model100
- https://archive.org/details/secrets-of-rom-revealed
Other even more valuable info:
- John R. Hogerhuis: "The best reference on file management is the NEC programmers reference."