Feet Inches and Sixteenths Conversion for the HP-48 
1995 Ted Cashin (Internet: dtbrejc@vax.dot.state.ga.us)

These programs do the same thing as HMS, HMS, HMS+ and HMS- except they are doing it with dimensions written in feet inches and sixteenths.

To convert 1-1 to a decimal fraction, enter as 1.0108 (which in ff.iiss format is 1 foot 1 inch and 8 sixteenths) and press FT to get 1.125. Pressing FIS will convert back to 1.0108.

FISA and FISM add and subtract (minus) dimensions in ff.iiss format. Therefore, to add 1-8 and 4-7 you would type in 1.0812 ENTER 4.0708 and then hit FISA to get 6.0404 which correlates to 6-4.

To get FIS to run correctly I had to throw in a small amount of error, but I dont think it will show up in typical civil engineering calculations. If you need the added accuracy, use the metric system.