“Hello, Z80 Calling…”

In the last installment of this series on Z80 machine code programming, we translated a program that took more than 200 bytes of machine code. It was so big that it could not quite fit into a computer with less than 2K RAM. This time, we will look at ‘ROM calls’ the machine code subroutines stored in the ROM of your computer. They can help keep your Z80 programs shorter, and save programming time and effort.