cpmcbfs is the use of the EldoS
Callback Filesystem library,
combined with the
project by Michael Haardt,
to allow Windows to mount CP/M filesystems.
This project is essentially the Windows equivalent to
It was written because some users of my
related projects prefer not to use command line tools.
Memotech computers used CP/M 2.2 filesystems, even when accessing
floppy disks from BASIC.
I include appropriate
diskdefs for these.
c:\cpmcbfs>cpmcbfs --help usage: cpmcbfs [flags] flags: -f,--format format format (default %CPMTOOLSFMT% or memotech-type18) -i,--image image image (must be specified) -u,--user user CP/M user (default 0) -v,--invert-case toggle case to match what CP/M uses -d,--drive d: mount as drive d: (default Z:) -r,--read-only read only access --install install cbfs driver --uninstall uninstall cbfs driver --status is the driver installed and running
Installation and uninstallation of the driver requires that you be running
as Administrator, and that
cbfs.cab be in the current directory.
Other uses of the program don't require this :-
c:\cpmcbfs>cpmcbfs --install Reboot the computer to complete the installation
Is the driver installed and running :-
c:\cpmcbfs>cpmcbfs --status Driver (18.104.22.168) installed, service is running
Normal use :-
c:\cpmcbfs>cpmcbfs -f memotech-type18 -i sddisc.bin -v Drive Z: should exist until you press Enter
In another Window :-
c:\>dir z:S*.COM Volume in drive Z is CbFS CP/M filesystem Volume Serial Number is 4350-4D5A Directory of Z:\ 01/01/1970 00:00 640 SDIR.COM 01/01/1970 00:00 384 STARTUP.COM 01/01/1970 00:00 5,248 STAT.COM 01/01/1970 00:00 1,280 SUB.COM 01/01/1970 00:00 512 SYSCOPY.COM 01/01/1970 00:00 45,952 SMG2M.COM 01/01/1970 00:00 35,968 SMG.COM 01/01/1970 00:00 15,488 STAR.COM 8 File(s) 105,472 bytes 0 Dir(s) 5,554,176 bytes free c:\>
Or use Windows Explorer or other programs to access files on Z:.
Using this program with devices directly requires that you run it as Administrator. You can enumerate suitable block devices like so :-
c:\cpmcbfs>cpmcbfs -i ? \\.\PhysicalDrive0 fixed 60801 255 63 512 465.76GB \\.\PhysicalDrive3 removable 15 255 63 512 117.66MB \\.\C: fixed 60801 255 63 512 465.76GB \\.\D: fixed 60801 255 63 512 465.76GB \\.\G: removable 15 255 63 512 117.66MB cpmcbfs: can't open ? (available devices were enumerated instead)
If you do this before you plug in your SD Card or other media, and then
again afterwards, you can easily spot the device to use.
Note how the SD Card I used above appears twice, once accessible as
\\.\PhysicalDrive3 and once as
If you get no devices listed, its probably because you're not running as
You can then use a command like this :-
c:\cpmcbfs>cpmcbfs -i \\.\PhysicalDrive3 -v
cpmcbfs is built using code from
it uses the same
c:\cpmtools\diskdefs configuration file,
and also uses the same filesystem format names.
-f is not used
cpmcbfs honors the
%CPMTOOLSFMT% environment variable, and failing that
falls back to
Note how the
-i argument must be specified,
and can refer to a device, such as an SD Card.
CP/M filesystems support the concept of 16 (or maybe even 32) users. You can specify the user when you mount.
Although CP/M actually uses uppercase filenames,
makes it look as if they are lowercase.
Ordinarily this is not a problem, except for the case where CP/M programs
actually break the rules and write files with lowercase names.
-v problem toggles the case so that the files appear
in uppercase on Windows.
cpmcbfs doesn't expose any special files such as
passwords or labels.
cpmtools does, as specially named files.
Read only status is affected by the 0200 weighted file permission.
Other file attributes are not supported.
cpmcbfs doesn't fabricate the execute bits if the
filename ends in
.com as Windows won't be able to
execute these files anyway.
cpmtools seems to have a bug in
cpmfs.c line 812,
causing it to apply exact file length logic to all versions of CP/M,
not just the ISX variant, as it should.
If you create a file and then don't write anything to it,
you seem to end up with a file containing 128 bytes of 0.
I think this may be a consequence of
cpmCreat locating a
file extent, prior to any
cpmWrite that might follow.
Attempts to create subdirectories will fail.
Attempts to create files with certain characters in their names (those not allowed by CP/M) will fail.
Attempts to change file ownership will fail.
Attempts to set creation, modification and access times may work on CP/M filesystem versions that support it, but silently do nothing otherwise.
I didn't keep all the
configure stuff in the original
cpmtools source code.
You can easily tweak the
if needs be.
At the moment, its only a command line program and there is no Windows GUI. It would be nice to be able to pick the file or device to mount and the drive to mount it as, and perhaps even be able to do this from Explorer. I don't know how to do this at present.
This software should not be sold.
EldoS sell licenses to use their CbFS library.
They also generously offer free non-commercial licenses to developers
creating software for non-commercial purposes (only).
A non-commercial license is used by
As I am using Visual Studio 2013 to compile the code, and the earliest Windows subsystem level it will let me specify to the LINKer is 5.01, this program requires Windows XP or later.
It is interesting to note that Michael Haardt wrote a folding editor
cpmtools source code is folded.
I too wrote a folding editor
cpmcbfs source code is also folded, although differently.
Hopefully the result isn't too crumpled.
cpmcbfs can be downloaded from