IBM ThinkPad A20 and A22 documentation in a 2.82 MB RAR archive, covering two models of the early A-series line. The file name lists no board number or revision, so open the archive to confirm whether it holds schematics, a service manual or both. It suits work such as tracing power rails, checking voltage regulators and locating connectors on these older planars. Verify the board labels against the drawings before relying on component values.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @IT_SERVICE_WORLD. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
7-ZipWinRARThe Unarchiver (macOS)