I wondered how images of real Plus D / Disciple / SAM Coupe disks were created and it seems like most of the ways to do this expired with the death of Dos at the turn of the millennium, so I hope this post will help people, as I struggled to find information on how to this in 2024.
Option 1 - Older Emulators / Utility Programs (Difficult in 2024)
Get hold of an old emulator (Realspec or Z80 for example) that has this feature, or a utility program such as SAMdisk https://simonowen.com/samdisk/
You'll need an old PC (P2/P3 vintage) with a real non-USB floppy drive, running DOS natively or a Windows OS sitting on top of DOS (anything Windows ME and before).
The old emulators access the floppy controller either directly or via BIOS INT13H calls and read all 10 sectors/track of the MGT format. New Operating systems do not allow direct access to the hardware so will not work, and likely won't work in something like DOSBox either.
Option 2 Linux (Easy with right hardware)
Get any real PC with a real floppy drive and controller (non-USB) and use the linux dd command with the correct device file for a 800Kb format. This may or may not work virtualised, but definitely works on real hardware.
Floppy to image:
Code: Select all
dd if=/dev/fd0u800 of=image.mgt conv=noerror,sync
Image to floppy:
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dd if=image.mgt of=/dev/fd0u800
If /dev/fd0u800 does not exist it can be created with
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sudo mknod /dev/fd0u800 b 2 120
Option 3 Gotek (Easy with right original ZX & MGT hardware)
Use a Gotek device (with Flash Floppy firmware) connected to a real plus D / Disciple & Spectrum as Drive A, and your existing floppy as drive B.
Create image files on the USB stick using an emulator (FUSE for example or the linux dd command to create a 8192000 byte length file) and use the original hardware to copy files using the SAVE D2 "Filename" to D1 command between the real floppy disk and the USB in the Gotek. You will need to format your image file either on the Spectrum or the emulator first using the format d1 command to lay down a MGT filesystem. Note snapshots and microdrive files cannot be copied this way. ]Alternatively you can create a perfect copy of the original floppy to the gotek using the "FORMAT D1 to 2" command on the Spectrum. D1 should be the Gotek with a blank MGT image loaded, D2 the physical disk you want to copy. The Spectrum will format the MGT image in the gotek and do a sector by sector copy of the real disk to the image. Of course you can do the reverse and lay down images from the Gotek to real floppies too.
See this post for correct Gotek setup viewtopic.php?p=139638#p139638
Options 2 & 3 will likely work for ST / Amiga (& other ?) formats, option 3 commands would need to be adapted for those native systems.
A note on USB floppy drives. They won't work for this task. None of them. The USB-if spec around which they are all designed does not cater for the 10 sector/track format and the drive cannot be made to do this (or rather the USB controller attached to the drive can't). if you use the dd method on a USB drive, you end up with a 9-sector/track copy and an image that doesn't work. Your only option is a real, honest to goodness floppy connected to a real honest to goodness floppy controller... USB won't cut it.
Does anyone know any other ways to do this ?