7 Feb
2011
7 Feb
'11
4:21 p.m.
By platter I meant the flywheel which turns the disk. Actually what I said
was misleading. It doesn't go through the circuit boards. Actually the top
circuit board is wrapped around the wheel while the bottom one is actually
underneath is.
I've taken some pictures...
http://www.classic-computers.org.nz/temp/lisa2-10-front-of-drive-800x600.jpg
http://www.classic-computers.org.nz/temp/lisa2-10-bottom-of-drive-800x600.j…
http://www.classic-computers.org.nz/temp/lisa2-10-bottom-of-drive-circuit-b…
I've looked up the ICs on the bottom circuit board. Apart from the
microprocessor(?) these are:
sn74ls26n - QUAD 2 -INPUT NAND BUFFER
mc3470ap- Floppy Disk Read Amplifier System
UPa2003c - NPN SILICON EPITAXIAL DARLINGTON TRANSISTOR ARRAY
8402 - rectifier?
74ls05n - Hex inverters with open collector outputs 14-PDIP 0 to 70
74ls04n - Hex inverter
sn75452BP - Dual Very-high Speed, High-current Peripheral Drivers
ne592n - differential video amplifiers
Would one of the last two be the ones controlling the motor?
By snooping around I've managed to find a service manual for the OA-D32V
400k drives on bitsavers. However, this covers an earlier model. The Lisa
2 has a OA-D34V and (as far as I can see) the circuit board at the bottom is
quite different. I'm not techo though, and I struggle to understand what's
written there. There may be hints but I can't interpret them. The manual is
at
http://bitsavers.org/pdf/sony/Sony_OA-D32_Microfloppy_Service_Nov83.pdf
I will re-read it again and see if it points to anything I can look at.
There is a troubleshooting chart but you seem to need some test equipment.
I appreciate your continuing suggestions, Tony and others. They are keeping
me from giving up entirely.
Terry
----- Original Message -----
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
To: <cctalk at classiccmp.org>
Sent: Tuesday, February 08, 2011 9:53 AM
Subject: Re: Apple Lisa 2/10 - Progress
If my search for a 400k drive comes up short and/or if time allows later
this week I'll work on seeing if I can ID the motor controller IC.
There are two PCBs in the drive, the top of the platter goes through one,
Waht do you mean by 'platter'? Surely not the disk itseld?
and the bottom of the platter goes through
another. When I open it up
again, I'll take some pictures.
it's very possible that one of the PCBs, probably the upper one, is the
spindle motor circuitry. If you are very lucky, it will be similar to the
motors in other Sony drives of the period, and will have similar control
circuitry.
I think there are some photos of a 'standard' Sony drive (in bits) in by
Flikr account (tonyduell). Do the parts look anythting like that?
-tony