[[The Mojon Twins]] are a company who release on multiple Z80 based machines.
This features [[MSX ]] computers, [[ZX Spectrum ]] computers and of course Amstrad CPC computers, all of them used to be quite popular in Spain in the 80's.
As a method they developed some Game engines in C language that can be easily ported on most of those machines with only few changes to manage the different video issues.