Here is a list of the ROMs inside my Master 512. Note that View, BASIC, ADFS and DFS have different version numbers to those in MOS 3.20. Note also that Viewsheet and EDIT are missing although these are listed in the MOS 3.50 user guide. They have been replaced by Exmon II and Inter-Word - perhaps this is something that one of the ROM boards does. DFS remains in socket 9 although it is a separate ROM inside my Master 512. I am not clear whether DFS is in the MOS ROM or not. I would be surprised if it was not included as the user guide says it is included and contains the ellipse drawing routine and sound routines.

I am wondering if the Switch is used to change which ROMs appear in the ROM table because I thought this machine was fitted with "Overview". I will test this out and report back.

Banks 0 to 3 are occupied by the ROMs on the first board. I presume that this means that the cartridge slots are disabled.