After talking to another Electron user on the 'phone and reading Howard Guppy's letter (EUG #6), it appears that there is some confusion as to how one can have both ADFS and DFS resident in the machine at the same time. If you have a Pegasus interface from Slogger providing you with DFS, it is simply a matter of purchasing a chip from ACP/Pres and plugging it into the interface to give both DFS and ADFS.
If you have either an AP3 (ADFS) or AP4 (DFS) interface from ACP/Pres, then they will again supply a chip or chips to give both ADFS and DFS and the interface is then referred to as an AP34.
If you are like me, and own an Acorn Plus 3, then you can obtain DFS software from ACP/Pres, either on disk for loading into ABR (or any sideways RAM), or in the form of a chip. (Contact ACP/Pres for details.)
DFS is used here when the software is only available on that format, and by having both filing systems resident at the same time, it only requires a COPY command to transfer that software to ADFS which is my preferred system.
The DFS filing system software is only loaded into ABR when I need it, thus freeing the ABR for other usage. External disk drives of either size can be connected to the rear of the Plus 3 for copying etc, and similar facilities exist for the other interface systems.
1st December 1992