cbmconvert release notescbmconvert 2.1.2Copyright © 1993–2003 Marko Mäkelä.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See the GNU General Public License for more details.
cbmconvert
cbmconvert
cbmconvertdisk2zipzip2diskThere are many archiving programs for the Commodore 64, all of
which are incompatible with archiving programs on other systems. This
cbmconvert utility tries to address this problem. It
extracts files from most known file formats and writes them to several
different formats, including some formats used by some Commodore 64
emulators.
This release of cbmconvert does not contain LHARC
support any more, since 1541 disk images (either plain or ZipCoded)
and Lynx archives are much easier to handle. If you need LHARC
support, get the older release, cbmconvert 1.1.
All code has been cleaned up. The file type management in
cbmconvert 2.0 is very flexible, and it is very easy to
add file types later. Currently cbmconvert reads the
following file types: Arkive, Lynx, ARC64/128, PC64, tape images (T64
and native Commodore C2N), disk images (1541, 1571, 1581, both native
and C128 CP/M format), and raw files. Conversions between 1541 disk
images and ZipCoded files can be made with the two supplied utilities
disk2zip and zip2disk.
Compile cbmconvert by typing make -f
Makefile.system where system
is one of the following:
amigaunixwin32The compilation should leave you with three executables:
cbmconvert, zip2disk and
disk2zip. Install these to your binaries directory, and
you are ready to go. Ask your system administrator and/or a local
guru if you do not know where to install the binaries. Or just use
them from the current directory.
16-bit compilers will probably have trouble with
cbmconvert. For instance, the standard file I/O library
in Borland C uses signed 16-bit integers for size_t,
which is not enough.
cbmconvertStarting with version 2.0.0, cbmconvert consists of
three programs:
cbmconvertdisk2zip1!filename..4!filename).zip2diskcbmconvertSince version 2.0, cbmconvert has independent file
reader and writer modules that are controlled through a main program.
There is only a command-line interface, but adding an interactive user
interface should be easy (any volunteers?).
cbmconvert reads all files in all input files you
specify on the command line and writes them in the format you specify.
If you want to copy only some files from a set of archive files to an
archive file or disk image, you will have to extract all the files to
a single-file format such as the PC64 format, and to copy the wanted
individual files to the output archive with another invocation of
cbmconvert.
You can get a list of cbmconvert options by invoking
the program without any arguments. cbmconvert supports
the following file formats:
-I and
-N options, read with the -n option.-P option,
read with the -p option.-L, read with -l.-C, read with -c. These files
are raw dumps of the data format the Commodore KERNAL routines
maintain. Block checksums and countdown leaders (0x89..0x81 for the
first copy and 9..1 for the second) are omitted, and the blocks are
not stored twice, but only once. The data consists of 192-byte tape
header blocks, 192-byte data file blocks, and arbitrary-length program
file blocks.-M[478], read with -m.-D[478], read with -d.
1571 and 1581 support have not been tested properly, and not
all 1581 features have been implemented.-a. No write support.-k. No write support.-t. No write support.Since cbmconvert has been written exclusively with
Commodore file names in mind, the support for CP/M disk images is a
bit clumsy. You may want to rename the files after extracting them
from the disks. For instance, if you have downloaded the CP/M disk
images from http://www.funet.fi/pub/cbm/demodisks/c128/, you can use the
following commands in bash to extract the files from the
disk images:
gunzip *.d64.gz
for i in *.d64; do mkdir ${i%.d64}; cd ${i%.d64}; cbmconvert -m ../$i; cd ..; done
for i in */*.prg; do mv $i "`echo ${i%.prg}|tr A-Z a-z`"; done
CP/M does not store the exact length of the files anywhere. That
is why many CP/M programs create files whose length is a multiple of
128 bytes. Text files in CP/M commonly use ^Z as an
end-of-file delimiter, and many programs fill the extra bytes in the
last 128-byte block of the file with this character. The CP/M
routines in cbmconvert does so as well, and it removes
the ^Z padding when reading the files. So, you could use
cbmconvert to remove the padding. But you may prefer the
following Perl 5 command:
perl -i -e 'undef $/; while (<>) { s/\032+\z//gs; print }' *
GEOS files on disk images will be handled transparently by converting them to and from the Convert format on the fly. All unused areas in the Convert file will be zeroed out, and all possible integrity checks will be made in both conversions. If the file is interpreted to be in GEOS or Convert format, and it fails in any integrity check, it will be treated as a native Commodore file.
You should note that Convert does not provide much safety for the file. For sequential files, the original file length is not stored anywhere. For VLIR files, it is, but even then there are no checksums.
As a speciality, all GEOS files have a file information block. The
contents of this block can be viewed with the simple Perl script
cvtinfo.pl that reads files in Convert format. It was just
a quick hack; feel free to make it more robust.
The GEOS routines have been tested with twelve 1541 disk images and
with several megabytes of *.cvt files, and they are
believed to be error free now. There were problems with the VLIR
sector format; Mr. Boyce's reverse engineered information about it was
incorrect, or at least inadequate.
The Commodore C2N tape format uses 187-byte file names that are
padded with spaces. On disks, file names are 16 bytes and padded with
shifted spaces. Since cbmconvert was designed primarily
for disk-based archives, it truncates tape file names to 16 bytes and
changes the padding from regular spaces to shifted spaces and vice
versa.
End-of-tape markers on C2N tapes are not converted.
There are two kinds of program files on tapes: relocatable program
files (type code 1, typically written in BASIC) and absolute program
files (type code 3, typically written in machine language). There is
no such distinction among disk files. When writing program files to
C2N archives, cbmconvert marks the files relocatable if the
least significant byte of their start address is 1. This typically
indicates a BASIC program.
On output, all file types expect PRG are converted to tape data files consisting of 191-byte fixed-length data blocks. The output to tape data blocks tries to mimic the Commodore KERNAL behaviour: a zero byte is written to the last data block after end-of-file, and the bytes following the zero byte are identical with the bytes in the preceding data or header block.
The data file padding in the last block is not detected or removed on input. Also, the padding is not added on output if the file length is an exact multiple of 191 bytes, even though the KERNAL routines would add an extra block whose first data byte is zero. This prevents data files from growing when they are imported from tape and exported again, but this may cause incompatibilities when writing a data file with exactly n·191 bytes of payload.
cbmconvertThe conversion may lose some file name or attribute information. In some cases, the filenames will be converted from PETSCII to ASCII or vice versa, and some PETSCII or ASCII specific characters will be lost in the conversions. Non-standard directory information available in some formats will be lost as well.
Lynx, Arkive and ARC allow duplicate filenames. But
cbmconvert detects them and refuses to write multiple
files with identical names to archives or to disk images. These
duplicates are often used as directory separators, to separate groups
of filenames. If you really need such separators, use 1-block-long PRG
or SEQ files with different names. For example, the first separator
can be a string of 16 dashes, the second one can be 15 dashes, and so
on.
Arkive also works on illegal file types that cannot be created without directly modifying the directory blocks. Such files will be converted to a supported file type. Files with unknown types on disk images will be skipped.
Handling the errors on disk images could be more robust. Not all
(typically BAM-related) errors on CBM DOS disk images are detected.
For erroneous 1541 disk images that do not work with the new
cbmconvert, you may want to try the disk2files
program of the previous release.
disk2zipThis program converts a standard 35-track, 683-block 1541 disk
image to ZipCode format. Because the ZipCode format stores the disk
identifier, this conversion adds information. You can use the
-i option to specify the disk identifier.
zip2diskZipCoded archives consist of four files prefixed with a number from
1 to 4, and an exclamation point. To extract an archive having the
files 1!disk, 2!disk, 3!disk
and 4!disk, type zip2disk disk. You may
then delete the original files with rm [1-4]\!disk or
similar. But note that some software (demos and copy-protected
software) may rely on the disk identifier, which will not be stored in
the 1541 disk image file.
Support for ZipCode SixPacks (1!!disk,
2!!disk, ..., 6!!disk)
could be added easily, but this format is used mainly for really
custom 1541 disks with abnormal low-level format, which
cbmconvert does not support.
Most of the cbmconvert package was written by Marko
Mäkelä. The original version appeared in 1993, and a complete rewrite
was started in 1997 and finished in 1998.
The zip2disk module was originally programmed by Paul David Doherty. The ISO 9660 compliant filename truncation algorithm was taken from the T64TOP00 utility created by Wolfgang Lorenz as a part of his now discontinued PC64 emulator.
Support for 1581 CBM DOS disk images was programmed by Pasi Ojala.
The ARC/SDA dissolving code was originally written by Chris Smeets.
The necessary information for supporting GEOS was provided by Joe Forster/STA, Doug Cotton, Alexander Boyce (author of the unofficial GEOS Programmer's Reference Guide) and by the anonymous author of the file "convertfrmt.txt".
You can download the latest source code distribution of
cbmconvert from http://www.funet.fi/pub/cbm/crossplatform/converters/unix/.
Binary distributions are available for Win32 and AmigaOS.
ChangeLog for detailsChangeLog for details-m and -M, so that
the C2N-related options can be -c and -C.cbmconvert. I slightly modified the magic cookie to
fix the problem.