Re:The BeOS file system, an OS geek retrospective
by ModernMech on Saturday July 07, 2018 @09:27AM
(#17478402)
> The angled sunlight triggered the write-protection mechanism
How does that even happen?
Re:The BeOS file system, an OS geek retrospective
by derefr on Wednesday July 11, 2018 @06:21PM
(#17510732)
Probably similar to how optical key-switches work: the floppy drive would shine a laser or LED through the write-protect notch and watch for it on the other side with an optical sensor to know whether the disk was write-protected.
So, in a not-write-protected disk (no through-hole), the laser light couldn’t make it through to the sensor... but sunlight sneaking in through the drive casing and under the disk still could.
https://www.haiku-os.org/legacy-docs/benewsletter/Issue4-22....
A Testing Fairy Tale
Two test engineers were in a crunch. The floppy drive they were currently testing would work all day while they ran a variety of stress tests, but the exact same tests would run for only eight hours at night. After a few days of double-checking the hardware, the testing procedure, and the recording devices, they decided to stay the night and watch what happened. For eight hours they stared at the floppy drive and drank espresso. The long dark night slowly turned into day and the sun shone in the window. The angled sunlight triggered the write-protection mechanism, which caused a write failure. A new casing was designed and the problem was solved. Who knew?