Now you have a choice to do one of the following option:<BR>
<BR>
* A. Replace the [[AMSDOS]] / CP/M bootstrap ROM with [[ParaDOS]] ROM inside the disc interface (optional, but it allows you to use the full capacity on 3.5" disc drive).
<BR>
'''RECOMMENDED''' to do so, if you're either using:<BR>
* [[464Plus_Conversion#Jonathanen.27s_Easy_Way_To_464.2B_Conversion|Upgraded CPC 464+ to 6128+ spec]] <BR>
* Unexpanded CPC 464 without CPC 6128 OS/BASIC ROM installed with both DDI-1 3" & 3.5" external disc drives connected only.