I'd like to have at least one external, USB HDD formatted to work on both Mac & PC. Especially so I can save iConnectivity drivers, updates etc. in a common, safe, off-line folder.
My previous understanding was that only FAT32 is supported between platforms. Is this still correct?
FAT32 is supported on both Windows and MacOS but is not recommended (especially for audio files) because of its file size limits. Don't use it.
The most common Windows drive format is the NTFS system, which modern Windows machines use by default, and which is the format most hard drives come with as standard. Macs can read NTFS, but normally can't write to it. If you want to write to NTFS on a Mac, the best solution is:
https://www.paragon-software.com/home/ntfs-mac/
This costs about $20, but is worth every penny if you do any kind of cross-platform work.
What's even better, if your drive is a Seagate you can download this version for free:
http://www.seagate.com/gb/en/support/downloads/item/ntfs-driver-for-mac-os-master-dl/
If you don't want to spend any money and don't have a Seagate drive, an alternative is to format your drive in the exFAT format, which is a Microsoft file system optimized for flash memory such as USB flash drives and SD cards, and is supported on both MacOS and Windows. Instructions on how to format a drive as exFAT can be found here:
http://www.laptopmag.com/articles/format-drive-for-windows-and-mac