Congratulations and well done.
To go a bit further with this example I would like to mention that there are at least 8 places in the code that are style bugs in how the statements are written.
Let me explain what a style bug is and why this is an important concept.
A style bug occurs when the syntax used in a statement is inconsistent with other similar statements in the same project.
Style bugs do not usually cause the application to fail to work properly. The problems that they cause are in the mind of the developer when projects become large. In a small project, like this one, inconsistent style is no real problem. In larger projects with hundreds of files, tens of thousands of lines of code and multiple developers then consistent usage of style is essential to maintain sanity.
When anyone starts to learn how to develop code it is important to experiment with various styles then adopt the style that helps you create clear and consistent code for the computer language you will use. When working with a group there needs to be a style guide that all group members approve of and will use consistently.
So for additional credit find at least 8 statements where I used correct but inconsistent syntax or formatting.
For even more credit add comments, in any language you are most at home with, that clearly and concisely describes how this example code works. Warning: This is something of a trap because I used an advanced technique or two when implementing the Timer Zero interrupt service routine. When you understand the HOW and more importantly the WHY of the choices I made for this implementation you will have learned a lot of important things about the PIC12F675 Timer Zero hardware.
