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Re: EDD Plus Card



Alex Freed wrote:
glen herrmannsfeldt wrote:


No, but it makes it easier to get the full capacity of the track.


Apple disk drives still never had any hardware to read the index hole.

Right.  And "easier" is in the mind of the designer.

Stripping the sensing LED/phototransistor out of the drive, together
with its read channel (which would *double* the number of serial read
lines from the Disk ][) simplified the drives and saved cost.

The formatting routines of the Apple II are software-adaptive to the
speed of rotation of the particular drive, and manage to use the whole
track quite nicely at the cost of just a few bytes of code.

-michael

NadaPong: Network game demo for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."