MPI floppy drive service manual

Tony Duell ard at
Thu Jan 31 17:16:51 CST 2008

There is currently an HP9826 in bits on my bench, this machine 
incorporates a single 5.25" floppy drive. Now must such machines used 
Tandon TM100-2As (slightly modified to HP spec), but this one has a 
different tye of drive. A label on it says : 

Magnetic Peripheals Inc
(A Control Data Company)
P/N 77711807

I am looking for a servicv manual for this drive, in particular 
_mechanical_ information.

Looking at the drive, all the electronics (inclduing the spindle motor 
speed cotnrol) is on one PCB on top. The spindle motor is the normal 
motor + tachogenerator at the rear left corner, driving the spindle by a 
blet on the underside. The head postiioner stepper motor is at the rear 
right corner, shaft vertical with a taut-band mechanism to move the 
heads. To the right of the stepper motor drum, attached to extensions of 
the head carriage, is some sort of damper unit.

The PCB might be HP special. In particualr there is a header connector to 
link up an external drive in-use LED. But I susepct it's closely related 
to a standard MPI drive.

I need to know how to dismantle the band mechnaism to remove the heads, 
and als what to do about the damper which is leaking grease onto the 
chassis (!).

Does anyone recognise that drive mechanism and know where I could find a 
service manual. I've not found anything on-line yet.

Also, does anyone have a proper data sheet for the MC3470 (disk read 
amplifier etc). The only one I can find on the web is the NTE one which 
doesn't have that much information in it.


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