All you have to do is to use -z1 -i4 as image parameters.
It's unclear what the track order should be (ie separated by side, or both sides together, etc) but all of those parameters can be changed via commands anyway.
Rob, you may want to redump some of those disks, as they contain errors.
DSQD MFM 256 bytes 16 80 x2
If you see one with *T warnings just add -k2 which makes the processing 40 tracks.
For single sided disks you may want to use -g0 or -g1 too.
It's unknown whether the single sided ABC disks are flippy, as no such disk has been dumped. Flippy disks would require two index holes for the disk in order to use side 1, or a flippy modified drive. Given that the system is using a generic MFM controller, it is very likely to need the index hole for correct operation, and hence single sided disks used as flippy disks should have two index holes - but of course this is not proven until such a disk has been dumped.
My problem: I'm trying to imaging some 8" disks. They should be: 8", 77tracks, 26 sectors/track, 256bytes/sector, 2-sides, MFM
I have tried three different disks and none worked. I use an old BASF6104 drive together with the FDADAP adapter. With this combination I can read DEC RX02 disks.
The BASF drive was originally used with the ABC800 computer.
I tried: dtc -p -fabc838_test.img -e78 -z1 -oe76 -oo8 -v360 -i4
I have a stream file if that is of any interest.
I decoded the disk with -v360 -z1 -i4 parameters and it's perfect except for one thing: track offsets.
Each logical track is 1 track earlier than its physical position.
You can compensate for this by -using -a-1 -b-1, but notice that track 76 on the other hand is where it should be.
This would suggest that:
- the disk was re-used
- it was reformatted with a drive that is misaligned by 1 track
- it was also formatted/used with a drive that was not misaligned.
Unless this is a one-off failure of stepping there is no way to read the disk correctly without:
- having a drive that can read to track-1 (since track 1 is at track 0, track 0 would be at track -1) on BOTH sides
- use the drive that was used to write the disk to read it - it's obviously misaligned
If however this is a stepper failure (track 76 being at the expected position suggests otherwise) you can try using the slow firmware - however that should be the default in any recent software package.