Probably a good opportunity to clarify the maximum storage supported by RomWBW.
Actually, the RomWBW storage drivers support up to 20GB. 😊 However, there are other constraints that are involved in real use.
The RomWBW OSes (CP/M, ZSDOS, etc.) handle a maximum of 256 8MB slices. This means that a single storage device could have as much as 2GB of CP/M storage. However, it is possible to place a FAT12/16/32 partition after the CP/M storage which could easily occupy the full remainder of the storage.
I think that Karl is referring to yet another constraint. Specifically, the CP/M and workalike OSes use a maximum of 16 drive letters (A-P) which matches Karl's comments. This is a constraint of the OSes, so nothing RomWBW can really do about it. With one slice per drive letter, this comes out to a maximum of 128MB of CP/M storage available at one point. Accessing the other slices of the 256 requires using the ASSIGN command to remap the drive letters as desired.
I know folks will quickly remind me that some CP/M replacement OSes (e.g., ZSDOS) do support a single drive letter with more than 8MB. However, RomWBW wishes to ensure compatibility of the underlying storage across all the OSes, so it uses the lowest common denominator which is 8MB.
Clear as mud?