Phew! well that was a mammoth run
73 8" IBM DisplayWriter floppies flux imaged, photographed and metadata captured.
Thank god this lot were mostly what looks like a batch of backups.
I would say ~70% had at least 1 bad sector (usually CRC) but when you consider they were last written in 1991, and had already been overwritten many times, that is an extremely good result.
It was a real treat to see some fully intact.
Interesting format - Single Sided, FM, Track 1 26 sectors 128bytes/sect and tracks 2-77 15 sectors@ 256 bytes/sect.
I am guessing that the DisplayWrite’s native character coding is using IBM’s EBCDIC.
Now on to the next lot of disks. 8–)
Congratulations on the progress. What are the gadgets that the disk drives are connected to?
I know what you mean there. I recently sectored imaged (ddrescue) a couple dozen 3.5" floppies and it was really pleasing to see how many disks read perfectly. Admittedly they were mid 90’s -early 2000’s, much younger than the 8" disks. It was especially cool to see disks that presented bad sectors on the first pass reveal all of their data on subsequent passes. I think the drive head was cleaning off layers of grime from the disk media but I cleaned the heads after every disk and didn’t see obvious dirt.
The cards are the CBMSTUFF SuperCard Pro which does the flux (.scp) images and the FDADAP floppy disk adapter which does the 50 pin Shugart to 34 pin PC cable conversion and automatically handles the “TG43” signal.
I have certainly had C64 and Amiga Disks behave the way you describe with second read being more successful.
This box of 8" ers was amazingly well preserved for their age. I actually only had to clean the drive every second or third run.
No shedding either which is amazing in itself for magnetic media of this age. I suspect that it I was to take one of these Diskette 1 single sided disks and reformat it it would last another 40 years!.
They are primarily legit IBM Diskette 1 brand disks, which is understandable considering they were used with an IBM DisplayWriter.