Re: archiving floppy disks, natively on CP/M

On 19/11/2024 3:23 am, Jeff Jonas wrote:

Is there any CP/M equivalent to Unix/Linux "dd"
or hex dump?

Back when I wanted to make images of my eight-inch floppies (in Dave Dunfield's Image Disk format - or .IMD files) I adapted the disk copy program for a Compupro/Godbout Disk-1 controller to produce a program called D2IMD.  It is able to read a disk image from one drive and write an .IMD disk image file to the other drive.  Usually the image fits due to detection of adjacent identical content sectors (e.g. those that contain 0xE5 bytes from formatting) which are stored a "Compressed" in the IMD file - but in the event that the IMD file fills the output disk, it closes the file and prompts for a second "continuation" volume.  When you transfer the multivolume files to your Linux/macOS system - just concatenate them to get a complete .IMD image file.  I've used these images successfully to boot floppy images under a suitably configured SIMH AltairZ80 simulator running on my Mac and Linux computers.
D2IMD is system specific and embeds a copy of the disk controller portion of the CP/M-Plus BIOS into the program.  If you have the sources to the CP/M-Plus BIOS for your single-board computer you should be able to adapt it to be used by D2IMD.  The source-code is up on GitHub in the d2imd folder at -
https://github.com/agn453/CPM-UG-Disks
Tony