NTFS

I’d really like Risc OS to be able to access and use the NTFS filing system by default. I believe that on www.osnews.com that someone has made a open source solution to this.

Would be nice.

nx

It would be an interesting way to get around DOSFS limitations for external storage devices.

I’m not sure if it could meaningfully be implemented within the standard RISC OS filesystem structure because, while RISC OS supports 64-bit quantities for disc geometries, there’s still a 32-bit limit (4GB) on file sizes; careless use of signed integers tends to restrict you to 31 bits (2GB). NTFS uses much larger widths than this. The port, then, would be troublesome.

Adding 64-bit versions of all file access SWIs gets around it, of course, but isn’t a job for the faint hearted.

It would be an interesting way to get around DOSFS limitations for external storage devices.

You could also make DOSFS into a full FileSwitch client, rather than an image filing system. Then it wouldn’t be hamstrung by FileCore’s 2GB maximum file size.

I’d like to see the entire FS stack looked at, anyway; there’s far too much duplication of functionality at present – especially on the ATA side of things – the SCSI stack’s pretty decent.

I don’t think I should mention CDFS, either ;)

Adding 64-bit versions of all file access SWIs gets around it, of course, but isn’t a job for the faint hearted.

Maybe, but it will have to be done. A 4GiB file size limit is absolutely unacceptable in this day and age.

Fourtunately thanks to this project we will be able to do it within the community. This way we can offer it as a soft-loadable version initially, so people can use and Castle can’t be blamed for putting out a potentially problematic OS component as part of a commercial product.

I’d like to see the entire FS stack looked at, anyway

I quite agree.

I don’t think I should mention CDFS, either ;)

Heh – now you have the sources to witness the full glory / horror (delete as applicable).

Another thing that would be nice is to sort out HForm. Currently it’s got a load of cruft in for ST506 discs, which has essentially been unused since 1994. Really it would be better to rewrite it in portable C, that way there’d be a cross-platform implementation for people who want to do things like format emulator images in Windows. There’s already acorn-fdisk which is able to cope with various RISC OS partitioning strategies – if there was a tool mkfilecorefs to create a FileCore disc structure that would help give the same interface on both RISC OS and other platforms. It’d have to be carefully designed to run in the same environment HForm does (from a floppy, with only the ROM OS present).

Is there any documentation of the E/F+ format anywhere, or is the HForm source the authority?

Is there any documentation of the E/F+ format anywhere, or is the HForm source the authority?

The Ursula Filecore changes functional specification(s) are probably the best documentation—http://developer.riscos.com/registered/acorn/docs/docs/api/ursula/