Peter,

The assembler doesn't need to do any floating point calculations in the precalculated lookup method.

You use a spreadsheet - its the best tool for the job. Its very easy to format spreadsheet results into assembler text.

You merely list all the display states 00 to 99, input the wheel dimension and timer speed and then write a generic formula to get the highest timer count for one display readout. Copy that formula into all states and you've got all your answers. Its easy to reformat the results directly into "DB 0004h,0043h," table results which can be cut and pasted into your assembly listing.

If you want another table for a different wheel size, just change that one cell and you get the new answers.

In my opinion you have to do spreadsheet modeling ANYHOW on a speedometer project (or any project) to determine what counter resolution is appropriate.

-Jay C. Box