https://github.com/howerj/ffs
Forth File System using the BLOCK word-set
https://github.com/howerj/ffs
block blocks dos file-system forth ms-dos-style simple subleq
Last synced: 3 months ago
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Forth File System using the BLOCK word-set
- Host: GitHub
- URL: https://github.com/howerj/ffs
- Owner: howerj
- License: 0bsd
- Created: 2024-04-04T18:33:41.000Z (about 2 years ago)
- Default Branch: master
- Last Pushed: 2025-11-19T22:57:23.000Z (7 months ago)
- Last Synced: 2025-11-20T00:22:28.952Z (7 months ago)
- Topics: block, blocks, dos, file-system, forth, ms-dos-style, simple, subleq
- Language: Forth
- Homepage:
- Size: 1.01 MB
- Stars: 7
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- License: LICENSE
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README
# Simple Forth File System based upon the BLOCK word-set
* Author: Richard James Howe
* Email:
* License: 0BSD / Public Domain
* Repo:
This is a simple Forth block based file system. See the Forth
file [ffs.fth][] for more information including documentation.
The file system provides a word-set that allows a user to
interact with a disk image like you would with a
[DOS][] based system.
This project works under and also
SUBLEQ eForth (see ).
Some quick notes and limitations:
* Files consist of *non-contiguous* Forth Blocks.
* Files still consist of Forth Blocks, so are multiples of
1024 bytes in size on disk (for example, if a file is a 100 bytes,
one block is used, if it is 1200 bytes, 2 blocks will be used).
* The maximum file system size is roughly 64MiB.
* The maximum number of files per directory is 31.
* Command lines are limited to 128 bytes, try to keep them below
80 chars however.
* The file system is reliant on the Forth Block word-set and
should run on even the most spartan Forth system so long as it
is present.
* File names are limited to 16 bytes in size.
* Some commands include; `edit`, `exe`, `ls`, `rm`, `rmdir`,
`mkdir`, `cd`, `pwd`, `tree`, `cp`, `rename`, `cat`, `hexdump`,
`more`, `df`, `halt`, `fdisk`, and `stat`.
* Full file path parsing is not available and most commands
operate only using the current working directory. For example
you cannot `rm a/b/c`, you would need to `cd a`, `cd b` and
then call `rm c`. This is not a limitation of the file system
but the tools built upon it. Some utilities can parse "." for
the current directory and ".." for the next directory up such
as "mv" and "cd" but most cannot.
* The file system is designed to run as a single user system,
there is no locking and global variables are used.
* Only one file system can be mounted at a time.
* Some commands are line oriented, others have block oriented
analogues such as "cat" (line oriented) and "bcat" (block
oriented). The block oriented utilities expect the files
given to them to formatted as a Forth Block would be.
* There is no redundant FAT block data structure like in
FAT-12/FAT-16/FAT-32.
* Low memory usage: The file system uses kilobytes of data
(and can be further reduced if features like editing are not
required). A handful of variables and buffers are used, along
with the Forth Block system (a Block System with a single buffer
would work).
* For a list of bugs or to-dos, search for the strings BUG and
TODO, this is a small project and whilst care has been taken
in programming it there are bound to be errors, errors which are
worked out with usage of the system. I would not yet trust it to
store data without loss, yet.
## Examples
The following section contains a few examples of how to use
the file system and associated commands. To run the SUBLEQ
eForth examples you will need [make][] and a [C compiler][]
installed and on your [PATH][].
### GForth
An example session:
mkdir example
cd example
pwd
edit test.fth \ Start editor commands
+ .( FIRST BLOCK ) cr
+ .( FIRST BLOCK, SECOND LINE ) cr
n
+ .( SECOND BLOCK ) cr
s
q \ Back to "DOS"
ls
exe test.fth
df
rm test.fth
ls
### SUBLEQ eForth
To run the SUBLEQ eForth system you will need to type:
make disk
This will make a bootable disk image that will work with
the SUBLEQ VM. It will take a while to do so.
Instead of saving to a file called `ffs.fb` the disk image
`disk.dec` will be updated after exiting from the SUBLEQ
VM cleanly.
The SUBLEQ VM File System can only allocate from a pool of
about 61 blocks, there are special files that are created,
such as `[KERNEL]` that allow file system access to the SUBLEQ
eForth image.
## Example Sessions
An example session recorded with [ttyrec][] (all shorter than
they should be because of problems converting the recording
to a GIF):
And another:
And another:
## References
*
*
[ffs.fth]: ffs.fth
[DOS]: https://en.wikipedia.org/wiki/DOS
[make]: https://www.gnu.org/software/make/
[C Compiler]: https://gcc.gnu.org/
[PATH]: https://en.wikipedia.org/wiki/PATH_(variable)
[ttyrec]: https://en.wikipedia.org/wiki/Ttyrec