Johan Koelman

Johan Koelman, alias Dr Beep, started coding in the early years of the ZX Spectrum. The nickname Dr Beep is a derative from "Dr Beat" from the Miami Sound Machine, adapted to the ZX Spectrum. He coded for YRS which was short for "Ymond Reconstruction Service" when hacking games. The first game Dr Beep hacked was Pyjamarama, followed by Automania.

After leaving the Ymond-region the name was just YRS as a brand.

In 1997 Dr Beep coded a ZX81 emulator running on a ZX Spectrum. Dr Beep has a passion in coding games in a small amount of memory. Most games are coded in just 1K of data. In 2011 Dr Beep tried coding a hires game in just 1K memory for the ZX81.

Between 2011-2015 more than 20 games in 1K are coded in hires for the ZX81.