I know that https://en.wikipedia.org/wiki/S2_Spreadsheet?wprov=sfla1 existed since '84 and was in use in disparate parts of the company (I hit the printer division in the summer of '88). IBM was still using mainframe tools, including FORTRAN and APL for engineering work, and we were using BASIC for some testing automation as well as stuff written in assembly (bit banging of parallel ports as GPIO).