How to calculate a promissory note with a balloon payment

[Angela Carter]

I have a property that I intend to carry the mortgage for. My exit strategy is to sell this note to a note buyer, so I am trying to write this in a way that they will appreciate.

Here are the numbers. Please tell me if you know how to calculate it?

100,000 purchase price
20,000 down payment
80,000 loan amount
10% interest rate amortized over
30 years
30,000 balloon payment in five years

What is the payment amount for this (not including taxes and insurance)?

Thank you!!!