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VirtualAcorn Technical support:
Renaming HostFS::HardDisc4

We have been asked a couple of times now about how to rename the HostFS::HardDisc4 mount. I don't recommend that you ever rename a harddisc (either real or virtual) that's used to store the RISC OS !Boot sequence. There can be many unexpected problems waiting to trip up the unwary. If you absolutely must rename the drive then read this article through a couple of times first. Make sure that you keep a backup of !Boot before you try this. If renaming HardDisc4 causes errors from RISC OS then you will need to revert to the original naming as we won't be able to help you put everything right.

Absolute path names

An absolute path name is one that provides a full description of a file location starting with the file system. an absolute path looks like this:


There's a high degree of probability that most entries in your boot sequence will use absolute rather than relative names. As an example suppose there is a reference to:


in the boot sequence. If you renamed HardDisc4, for example suppose it was renamed as Jim, then the real path to the file would now be:


But RISC OS would still be looking for:


So RISC OS would no longer "find" !Printers and would throw up an error on booting. You would need to go through every file in the !Boot sequence and replace every occurance of:


and replace it with:


Doing this could prove to be an uphill task as there can be hundreds of files in a RISC OS !Boot sequence.

Relative path names

A relative name provides a file location as a route from where we are now to where the file we want is. For example, up one folder, up the next folder, down this folder etc. This sounds vague but it's a perfectly reasonable way to describe a file location. For example:


This translates as directions from the location of the boot suquence (<Boot$Dir>) to the file 'Blue1'. The strange looking .^. means go up one folder.

If the entire RISC OS !Boot sequence used relative names. for example:


then renaming HardDisc4 wouldn't cause as many problems. Some applications would still complain that they can't find things. The RISC OS pinboard would also fail as it only uses absolute names.

You can "rename" the existing HardDisc4 from the HostFS control panel by making a new HostFS mount that points to the HardDisc4 folder (as seen by Windows) with a new name (for example Jim). You would then have 2 HostFS mounts that point to the same Windows folder. Removing the one named "HardDisc4" would just leave the one called Jim, which would then become the first drive, and hence the boot drive.

Also note the mount flags for Bootable and Show DOS extensions need to be set so the new mount has the same flags as the old HardDisc4 mount.

However I really don't recommend doing this, if you really must and are prepared for the potential problems then firstly back up the file:

C:\Program Files\VirtualAcorn\VRPC-xxx\Models\Arm 7 RISC OS xxx(Jit)\Model.cfg

(where xxx is determined by your version of VirtualAcorn)

So if it all goes wrong you can put things back. Also note that if you do rename the harddisc and it does all go wrong we won't be able to provide any support and will simply tell you to put it back, or even to re-install your VirtualRPC. You have been warned!

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Last Edit Date 29/03/21