TC.EXE - Time calculator

This very old piece of software (binary code written in 1989 by Alf Björnberg) is useful for calculating one duration as percentage of another. It works on PCs as a DOS routine. Just download TC.EXE to your desktop and click on it to run (no installation needed).

For example, having calculated the total duration of all of Morricone’s music cues for The Mission (1986) to 1 hour, 12 minutes and five seconds (how did I do that?), I wanted to know what proportion of the film (total running time 2 hours, 4 minutes and 55 seconds) contained music. This page explains how to do that. Other functions are listed here.

Step 1. Download TC.EXE to your computer

Step 2. Run TC.EXE from your computer. You should see something resembling this

Step 3. Enter the total running time of the film as three separate numbers, like this:
            2 <– 04 <– 55 (<– = Enter or Return key)

Step 4. Press <– (Enter) again and then % to select percentage calculation:

Step 5. Press T to select percentage calculation of two durations, in this case to find out what
          percentage of 2hr 4min and 55sec is 1:12:05. (Pressing N lets you calculate n% of
            2:04:55, e.g. 25% of 2:04:55 = 0:31:14, rather than what percentage one duration is of another
          So, press T!

Step 6. Enter the total duration of all music cues (1 hour, 12 mins, 5 seconds) like this:
           1 <- 012 <- 05 (<- = Enter or Return key)

Step 7. Press <– (Enter) for the last time to reveal the answer.

The answer is 57.7%.
In other words music is present for well over half the total duration of The Mission.


The on-screen instructions for TC.EXE are a bit difficult to read. Here they are much clearer. Options after entering the first time value for each calculation are:

Key to
Operation to perform
Add a time value to the time value just entered
Subtract a time value from the time value just entered
Multiply the time value entered by a numeric value
/ then N
Divide the time value entered by a numeric value (not 0!)
/ then T
Divide the time value entered by another time value (not 0!)
% then N
Calculate the time value that is n% of the first time value
% then T
Calculate the % of 1st time value represented by a 2nd value
Convert mins>60 or secs>60 to hrs:mins:secs
1, 2, 3
Get 1st, 2nd or 3rd value from displayed previous calculation and insert as 2nd value in current calculation
View previous calculations (if any)
M then F1
Help with memory functions
Cancel, i.e. Erase all entered input in current calculation
Toggle output to printer