On Tue, 2004-09-07 at 11:03 -0400, David V. Corbin wrote:
>>
Jules, yes a large hard drive seeing would be very
>> interesting. <snip> .... the size of a washing machine but
>> all glassed in top... lots of power lots of heat......
While I have not been following every message in this thread..It seems like
a replica might be the best way to go. Could definitely "play some games" to
make it more reliabile, lower-power, etc. Whould stilll give the look and
feed of the classic drives [oh how I remember a row of RP-06's spinning
away!]
Yep - I was going to do this with a more modern drive (5.25") and stick
it in a wall-mounted cabinet along with a keypad and display (I've got
some nice vacuum-fluorescent 7-segment displays lined up for the display
bit).
I'm hoping I can replace the drive's cover with a homebrew perspex one
without too much crud getting in - data reliability isn't important but
I'm not sure how reliable any embedded servo information will remain.
Pick one of the stepper-motor drives -- they don't have servo information
to worry about!. Some of them, Rodime being one that I remember. do still
take _some_ information off the platter (like the position of the index
pulse -- the hall sensor generates several pulses per revolution, it
takes a single pulse from the disk at power-up to determine which of them
is the index), but I guess you can find one that doesn't actually need to
read anything.
Other option is to drive the head voice coil directly - in theory that
bit's not too hard, but a lot of drives are clever enough to shut down
the spindle motor if something's amiss (such as the heads not responding
to movement from the logic!). I'm not sure how easy it'd be to work out
how to drive the spindle motor.
Try an ST506 or ST412. Certainky on the latter the spindle motor driver
is a separate PCB, and the _only_ connections to the rest of the drive
are +5V and ground. That's also a stepper-motor drive... Can you find a
dead/dying ST412?
-tony