3 ms·
Yeah, constant angular velocity (hub motor RPM is fixed) vs. constant linear velocity (linear speed over the disk is fixed). If memory serves, the 800K Mac and
by philpem 8y ago
Yeah, constant angular velocity (hub motor RPM is fixed) vs. constant linear velocity (linear speed over the disk is fixed). If memory serves, the 800K Mac and Commodore 1541 disks were actually Z-CLV or Zoned-CLV -- where the drive speed changes every "n" tracks. The reason you do ZCLV is that it reduces the complexity of the controller hardware (fewer taps on the clock divider).
The fun trick is, with a drive controller which works based on "time between pulses" (DiscFerret, Catweasel, etc) you can do all of the above with a CAV disk drive just by tweaking the read/write clock. Same trick probably works for discrete drive controllers like the 765 and 1771 (I say probably because I haven't checked the datasheet!).