Very interesting, thanks for posting! There were many small or virtually no-name CP/M systems sold in the '70s and '80s that looked like that. The floppy formats during that time could vary a bit but I think the article somewhat overstates the difficulty of reading them.
In the Data Recovery seminars I taught back in the '80s I frequently demonstrated recovering files from damaged floppies. In a class demonstration I would format a diskette, fill it with files, then use a pin or needle to poke a hole in the disk. Since the disks were double-sided this would in fact cause at least two sectors to become unreadable, one on each side of the disk. What was really interesting was that these sectors would be on different tracks since the tracks on one side of a floppy are offset from those on the other side. In any case I then would use disk editor software to read the damaged files, working around the damaged sectors. Worst case I would lose two sectors worth of data, amounting to a paragraph or two (512 bytes per sector for a total of 1,024 bytes) in one or two files. In most cases I could get partial sector reads and would only lose a few words or sentences from one or two of the files.
The most heroic floppy data recovery I know about I actually witnessed during a private tour of the DOD Computer Forensics Lab
in 1997. In that example several floppy disks containing evidence in a murder case were destroyed by saw-toothed pinking shears
. After creating a splicing procedure they were able to splice the disks back together
and successfully read them. This story was even covered on an episode of the Forensic Files titled Shear Luck
I still have quite a few 5.25" floppies with data on them from that time, some even from CP/M systems. I haven't read them in a while but they have been properly stored and appear to be in perfect condition. One day I plan on resurrecting my "Darth Vadar" Apple ][+
with a Z80 card (enabling it to run CP/M) to see what can or can't be read. Scott.