Already been done: see http://osxbook.com/software/ancientfs/

Arnold

Clem Cole <clemc at ccc.com> wrote:

> ​Will Senn asked
>
> > Supposing I created a byte faithful representation of a V6 filesystem
>
>  > on my mac, would I then be able to load the file in simh as an RK05 and
> >  > mount and access its files and directories from a V6 instance?
> >
>
> ​Not 100% sure how to parse this... but that is exactly how simh (and
> Ersatz11)​
>
> ​ work.
> You have a UNIX file on your mac and at the simh interactive command
> system, you "attach" it as the data for the simulated RK05.
> ​But it's a manual process to do the attachment AND more importantly,
> since Mac OSx just sees it as bits, as a minimum you need to write tools to
> push/pull V6 "files" from the image.  This is the same as the "DOS Tools"
> trick you see in a lot of UNIX systems that know how to "grok" DOS/FAT file
> system images.   You would need to do the same thing.  If you poke around
> the Warren's TUHS archives, you might find some of this already there.
>
> ​What many of us do it attach a file as a virtual disk but instead of using
> a UNIX file system format, use it is a tape image.   Then use tar/cpio or
> whatever if you already a tool on both sides that can interpret the bits.
> Hence, the v6tar discussion of a few weeks ago.   The UNIX ar(1) format is
> sometimes used also, since it was common.   cpio -c also works, but that
> was not on the research systems.​   My old room mate, Tom Quarles, wrote a
> really good ANSI tape reader/writer for BSD UNIX.  That should back port to
> v6 with a little work, particularly if you the "typesetter C" compiler for
> V6 which supported enough of the V7 C.   The advantage of the ANSI tape
> format is that its common with the DEC systems as well as UNIX.
>
>
> That said, you can be smarter and more automatic.   As Noel says Ersatz11
> supports a virtual shared disk (the same way VMware and Parallels) do.
> Writing such a device for simh would be cool and in fact useful for many
> different emulators.  Warning there are a lot of dragons hidden with such a
> shared FS.   At is definitely doable, but is going to take some work.
>
> The other thing you could do that might be a little less work, but would be
> Mac specific, is Mac OSX has the FUSE file system emulation that stuff that
> Google released.  If hacked up support for the old Unix FS, you could mount
> the V6 "disk" image as Mac OSx disk and see the bits with normal tools.
> I've thought about doing this but I have never had the time.  If I ever
> became a serious user of the simh, I would probably want something more
> like this.
>
> Clem