Midnight Commander virtual filesystem for C64 disks

This extfs provides an access to disk image files for the Commodore VIC20/C64/C128 for Midnight Commander. It requires the utility c1541 that comes bundled with Vice, the emulator for the VIC20, C64, C128 and other computers made by Commodore.

Features

• View, remove, copy files in and out of the image,
• Support for read from and write to d64, d71 and d81 images,
• Gzipped disk images support,
• On fly characters remapping (see below).

Remarks

Due to different way of representing file entries on regular Commodore disk images, there could be issues with filenames that are transfered from/to the image. Following rules was applied to represent a single file entry:

1. An extension is attached to the end of a filename depending on a file type. Possible extensions are: prg, del, seq, usr and rel.
2. Every non-ASCII character (which could be some of characters specific to PET-ASCII, or be a control character) will be replaced by dot (.), since c1541 program will list them that way.
3. Every slash character (/) will be replaced by pipe character (|).
4. Leading space will be replaced by tilda (~).

While copying from disk image to filesystem, filenames will be stored as they are seen on a listing.

While copying from filesystem to disk image, filename conversion will be done:

1. Every $ and * characters will be replaced by question mark (?)
2. Every pipe (|) and backslash (\) characters will be replaced by slash (/)
3. Every tilde (~) will be replaced by a space
4. prg extension will be truncated

Representation of a directory can be sometimes confusing - in case when one copied file without extension it stays there in such form, till next access (after flushing VFS). Also file sizes are not accurate, since directory entries in CBM format have sizes stored as 256 bytes blocks.

Screens below shows how it looks like on real C64 machine and its representation on Midnight Commander listing.

In media directory you can find the test.d6z gzip compressed D64 image file.

Rquirements

• Python 3.6 or higher (checked recently with 3.11)
• Vice installation (c1541 program in path)

Installation

• copy uc1541 to ~/.local/share/mc/extfs.d/
• add or change entry for files handle in ~/.config/mc/mc.ext:

# Disk images for Commodore computers (VIC20, C64, C128)
[d64]
Regex=\.(d64|d71|d81)$
RegexIgnoreCase=true
Open=%cd %p/uc1541://
View=%view{ascii} c1541 %f -list

[d6z]
Regex=\.(d[678]z)$
RegexIgnoreCase=true
Open=%cd %p/uc1541://
View=%view{ascii} t=$(mktemp); zcat %f > ${t}; c1541 ${t} -list 2>/dev/null; rm ${t}

Configuration

Here are specific for this script variable, which while set, can influence script behaviour:

• UC1541_DEBUG - if set, uc1541 will produce log in /tmp/uc1541.log file.
• UC1541_VERBOSE - if set, script will be more verbose, i.e. error messages form c1541 program will be passed to Midnight Commander, so that user will be aware of error cause if any.
• UC1541_HIDE_DEL - if set, no DEL entries will be shown.

Changelog

• 3.6 Fixed line matcher for directory entries.
• 3.5 Drop Python2 support.
• 3.4 Code cleanup. Removed dummy logger class and sys.args based argument parsing.
• 3.3 Added support for .d71 and .d81 disk images.
• 3.2 Changed shebang to python executable instead of python3
• 3.1 Argparse on Python3 have different behaviour, where if no subcommand is provided, it will pass anyway. Fixed.
• 3.0 Added beta quality Python3 support
• 2.8 Treat non standard discs a bit better
• 2.7 Added support for gzipped disk images
• 2.6 Added mkdir and run handling (or rather lack of handling :). Minor refactoring.
• 2.5 Fixed bug with filenames started with a '-' sign.
• 2.4 Fixed endless loop bug for reading directory in Python implemented directory reader.
• 2.3 Re added and missing method _correct_fname used for writing files into d64 image.
• 2.2 Fixed bug(?) with unusual sector end (marked as sector 0, not 255), causing endless directory reading on random locations.
• 2.1 Fixed bug with filenames containing slash.
• 2.0 Added reading raw D64 image, and mapping for jokers. Now it is possible to read files with PET-ASCII/control sequences in filenames. Working with d64 images only. Added workaround for space at the beginning of the filename.
• 1.2 Added configuration env variables: UC1541_VERBOSE and UC1541_HIDE_DEL. First one, if set to any value, will cause that error messages from c1541 program will be redirected as a failure messages visible in MC. The other variable, when set to any value, cause del entries to be not shown in the lister.
• 1.1 Added protect bits, added failsafe for argparse module
• 1.0 Initial release

License

This software is licensed under 3-clause BSD license. See LICENSE file for details.