This modification will allow you to have two DOSs in a CPC6128 without the need of an addition additional PCB. By replacing the standard 16K EPROM with a 32K and switching the MSB (A14), you can choose the DOS that the CPC uses.
If you don't like making changes inside your CPC, then check out the [[LowerROM|LowerROM Board]] external solution.
== Warning / Disclaimer ==
The EPROM should be burnt with whatever two OSs you wish to have, the first OS is saved from &0000 to &3FFF and the second OS should be located from at &4000 to &7FFF.
The ROM image below is a single 32K file with AMSDOS and ParaDOS.