Toshiba A100 archive in RAR form, 1.97 MB in size. The name states neither a board number nor revision nor the contents, and the Satellite A100 series used several mainboards, so verify the ODM code on the PCB matches the files inside. Typical packages of this kind contain a schematic used to follow power rails and signals, check charging and regulator circuits, find the BIOS chip and track down components on a shorted line. Extract it with any RAR-capable tool.
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 @alischematics. 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)