Lately, I've been playing around in v6 unix and mini-unix with a goal of better understanding how things work and maybe doing a little hacking. As my fooling around progressed, it became clear that moving files into and out of the v6 unix world was a bit tedious. So it occurred to me that having a way to mount a v6 filesystem under linux or another modern unix would be kind of ideal. At the same time it also occurred to me that writing such a tool would be a great way to sink my teeth into the details of old Unix code. I am aware of Amit Singh's ancientfs tool for osxfuse, which implements a user-space v6 filesystem (among other things) for MacOS. However, being read-only, it's not particularly useful for my problem. So I set out to create my own FUSE-based filesystem capable of both reading and writing v6 disk images. The result is a project I call retro-fuse, which is now up on github for anyone to enjoy (https://github.com/jaylogue/retro-fuse). A novel (or perhaps just peculiar) feature of retro-fuse is that, rather than being a wholesale re-implementation of the v6 filesystem, it incorporates the actual v6 kernel code itself, "lightly" modernized to work with current compilers, and reconfigured to run as a Unix process. Most of file-handling code of the kernel is there, down to a trivial block device driver that reflects I/O into the host OS. There's also a filesystem initialization feature that incorporates code from the original mkfs tool. Currently, retro-fuse only works on linux. But once I get access to my mac again in a couple weeks, I'll port it to MacOS as well. I also hope to expand it to support other filesystems as well, such as v7 or the early BSDs, but we'll see when that happens. As I expected, this was a fun and very educational project to work on. It forced me to really understand what was going in the kernel (and to really pay attention to what Lions was saying). It also gave me a little view into what it was like to work on Unix back in the day. Hopefully someone else will find my little self-education project useful as well. --Jay
[-- Attachment #1: Type: text/plain, Size: 1041 bytes --] On 2/22/21 10:41 AM, Jay Logue via TUHS wrote: > Lately, I've been playing around in v6 unix and mini-unix with a goal > of better understanding how things work and maybe doing a little > hacking. As my fooling around progressed, it became clear that moving > files into and out of the v6 unix world was a bit tedious. So it > occurred to me that having a way to mount a v6 filesystem under linux > or another modern unix would be kind of ideal. At the same time it > also occurred to me that writing such a tool would be a great way to > sink my teeth into the details of old Unix code. > ... > As I expected, this was a fun and very educational project to work > on. It forced me to really understand what was going in the kernel > (and to really pay attention to what Lions was saying). It also gave > me a little view into what it was like to work on Unix back in the > day. Hopefully someone else will find my little self-education > project useful as well. > > --Jay > Yay! I for one, will appreciate this! Will [-- Attachment #2: Type: text/html, Size: 1522 bytes --]
[-- Attachment #1: Type: text/plain, Size: 1265 bytes --] Please let us know how you go with the Macs. The system interfaces have become more refractory lately, with virtual file systems a particular concern. -rob On Tue, Feb 23, 2021 at 4:11 AM Will Senn <will.senn@gmail.com> wrote: > On 2/22/21 10:41 AM, Jay Logue via TUHS wrote: > > Lately, I've been playing around in v6 unix and mini-unix with a goal of > better understanding how things work and maybe doing a little hacking. As > my fooling around progressed, it became clear that moving files into and > out of the v6 unix world was a bit tedious. So it occurred to me that > having a way to mount a v6 filesystem under linux or another modern unix > would be kind of ideal. At the same time it also occurred to me that > writing such a tool would be a great way to sink my teeth into the details > of old Unix code. > ... > As I expected, this was a fun and very educational project to work on. It > forced me to really understand what was going in the kernel (and to really > pay attention to what Lions was saying). It also gave me a little view > into what it was like to work on Unix back in the day. Hopefully someone > else will find my little self-education project useful as well. > > --Jay > > Yay! I for one, will appreciate this! > > Will > [-- Attachment #2: Type: text/html, Size: 1934 bytes --]
On Plan 9: http://9p.io/magic/man2html/4/tapefs On Unix: https://9fans.github.io/plan9port/man/man4/tapefs.html Cheers, Anthony
Jay Logue via TUHS <tuhs@minnie.tuhs.org> wrote: > ... The result is a project I call retro-fuse, which is now up on github > for anyone to enjoy (https://github.com/jaylogue/retro-fuse). Very cool! > Currently, retro-fuse only works on linux. But once I get access to my > mac again in a couple weeks, I'll port it to MacOS as well. I also hope > to expand it to support other filesystems as well, such as v7 or the > early BSDs, but we'll see when that happens. I note that Linux already has the 'sysv' kernel module which supports System V short-filename file systems. Enhancing that for V7 and early BSD may be a faster route to having such file system images be mountable. (But perhaps less fun than a FUSE filesystem that uses original Unix code.) An enhanced version of the sysv kernel module that supports filesystems from the AT&T Unix PC / 3B1 is available at https://github.com/dgesswein/s4-3b1-pc7300. Arnold
arnold@skeeve.com writes: > Jay Logue via TUHS <tuhs@minnie.tuhs.org> wrote: > >> ... The result is a project I call retro-fuse, which is now up on github >> for anyone to enjoy (https://github.com/jaylogue/retro-fuse). > > Very cool! > >> Currently, retro-fuse only works on linux. But once I get access to my >> mac again in a couple weeks, I'll port it to MacOS as well. I also hope >> to expand it to support other filesystems as well, such as v7 or the >> early BSDs, but we'll see when that happens. > > I note that Linux already has the 'sysv' kernel module which supports > System V short-filename file systems. Enhancing that for V7 and early > BSD may be a faster route to having such file system images be mountable. > (But perhaps less fun than a FUSE filesystem that uses original Unix code.) > > An enhanced version of the sysv kernel module that supports filesystems > from the AT&T Unix PC / 3B1 is available at > > https://github.com/dgesswein/s4-3b1-pc7300. > > Arnold NetBSD has v7fs which claims to be able to deal with the 7th Edition filesystem. -- Brad Spencer - brad@anduin.eldar.org - KC8VKS - http://anduin.eldar.org