2275 Lotus 1-2-3 Worksheet 9.8 Millennium Spreadsheet Lotus 1-2-3 Workbook is a spreadsheet program produced by the Lotus Software Group (later acquired by IBM). The original release was in 1983 and it has been discontinued since 2013. The original 1-2-3 files have .wks extensions. Version 2.0 originally used a .wk1 extension but this was changed quickly to .wk2 and after this the number in the extension corrolates with the version number. Some later versions have the extension .123 248 Aarhus City Archives / Aarhus Stadsarkiv 16 Oct 2021 16 Oct 2021 application/vnd.lotus-1-2-3 MIME application/x-123 MIME fmt/1453 PUID 123 File extension 1817 Lotus 1-2-3 Worksheet Version 9.8 Millennium Section Record Type = 0, record length dec 26 = 1A; file format version number = hex 05100400 1 Absolute from BOF 0 0 00001A0005100400