On Tue, 24 Jan 2023, Chris via cctalk wrote:
C: Remember though they are 2" disks. And shootimg from the hip, if
coercivity wasn't on spec, would a) would that pose a threat to the disk
dribe's circuitry.
no, wrong coercivity won't hurt the drive.
When the college purchasing agent was sleeping with the Roytype salesman,
they gave us HD (1.2M/600Oe) disks for the TRS80s. Disk would format and
write, seemingly OK. A few minutes later, it was blank again.
("Good morning Mister Phelps; if you or the Mission Impossible team are
captured, we will disavow all knowledge. This message will
self-destruct.")
And b) could the circuit be tweaked to work with what's there.
possibly. different level of write current, etc.
I'm not sure how this could be worked out, but it seems to me there
could be a way to modify a drive so that it could measure a disk's
coercivity.
Try different write currents, and see what the thresholds are?
Knowing what it already has for a write current might give a clue.
There was that scene in the Jackal where a hacker woman claimed she
could read a card's magnetic strip with a disk drive. I guess it's
possible the more I think about it.
I think that a tape recorder head might work for a BART card, . . .
