I have successfully duplicated disks I own (and written disks from images of ones I don't) with ImageDisk on a DOS PC, so I don't think it's a terribly exotic format. Based on the headers of the existing disk images, I believe they're 256 byte sectors with 16 sectors/track, 80 tracks, double sided.
My test disk before I try the factory media is a double-density floppy I created from a TeleDisk image. I wrote it on a high-density drive and confirmed that it works as expected on the 9100 hardware.
I created a stream image of the disk, then wrote it back to a blank media. I was able to boot the hardware with it, so I believe the stream image is good. Where I've been stumbling is trying to decode the stream to create a raw image.
Based on the headers in the TeleDisk image, I believe these are 256 byte sectors, 16 sectors/track, 80 tracks, 2 sides. Based on three bands in the scatter plot, I believe they're MFM encoded. I'm trying to decode with:
Code: Select all
dtc -fout.img -i4 -dd0 -z1 -n16 -m1 -fsd14/track -i0 -e83
I've tried every possible sector size (removing the number of sectors/track when I do so), but haven't been able to get the data to decode.
Here's scatter plots of sector 0 on sides 0 & 1 of the disk:
Can someone suggest how I might get this image to decode?