Re: Widget Repairs

What does the light on the top of the controller do? (Not the READY light that faces forward)

I recall from my drives that after the spindle comes up to speed, when the brake releases the light on the top of the controller flashes once.

The device pointing at the spindle motor is a coil & magnet sensor (don't hall sensors need 3 wires?) which reads the drive speed, and the track 0 pulse. Adjusting it would require a low level format.

Status to the Lisa will all come from the "Widget Controller" board on the top. On both of my drives the large chip in the PLCC socket had badly corroded pins. Removing it and cleaning the pins mechanically fixed many odd problems.

If the brake coil is bad, you could move it out of the way for testing. Note that if you swap the motherboard you have to re-adjust the pots. I think this adjustment needs doing if the head servo board is swapped too.

The head voice coil can't make much torque. If it gets a bit gummy the drive won't initialize. With the disk spinning and the brake off you can grab the shaft at the bottom and rotate it a bunch to free it up. I'd unplug the head connector first, though.

-J

On Thu, Jan 3, 2019 at 6:59 PM Tom Stepleton <stepleton_at_email.domain.hidden> wrote:

> One quick reply... and you'll have to forgive me for not remembering the
> details of software I wrote :-)
>
> NeoWidEx is a bit too timid about dealing with something that it doesn't
> think is a Widget.
>
> First of all, whenever you select any of the commands from the menu, if it
> hasn't had a chance to talk to the disk yet, it requests sector $FFFFFF to
> find out what's attached. Then, if the disk doesn't respond in a Widgety
> way, it refuses to run any of the Widget commands.
>
> This is probably a bit too cautious and, in your case, probably unhelpful.
> If I remember the Widget ERS document, a number of the low-level commands
> may still work. In particular, you might be able to use the FULL STATUS or
> SERVO STATUS menu options even when the Widget hasn't been able to bring
> itself up successfully (no guarantees though). This could help you in your
> diagnostics.
>
> You would need to disable the NeoWidEx code that does the check in order
> to do this. I don't remember what the best way to do this would be, but if
> you began your search here:
>
>
> https://github.com/stepleton/NeoWidEx/blob/master/NeoWidEx_CMD_Read_Controller_Status.X68#L25
>
> perhaps descending into WIDGETCHECK if you want:
>
>
> https://github.com/stepleton/NeoWidEx/blob/master/NeoWidEx_WIDGETINFO.X68#L42
>
> you might come up with a quick hack. For example, it might not be too
> tough to hack the NeoWidEx binary on a .dc48 disk image to have WIDGETCHECK
> execute an RTS immediately...
>
> --Tom
>
> On Thursday, January 3, 2019 at 4:10:06 PM UTC, Ray Arachelian wrote:
>>
>> Meta-Meta: sending email to lisalist via my gmail account is also broken,
>> so there's some serious issues with LisaList, if you've posted recently and
>> don't see your email make it to the list, try logging in to google via a
>> web browser and then go to https://groups.google.com/d/forum/lisalist to
>> repost anything that hasn't shown up. I'm not sure if this will show up,
>> but trying...
>>
>> ---
>>
>> Meta: I've sent this last night from my non-gmail email, and it hasn't show up on LisaList, I wonder if Google Groups is blocking non-gmail addresses. I've seen other reports of other folks not being able to post here a few months ago.
>>
>> So resending from my gmail address. If that's what's going on, shame on you google!
>> Edit: Nope, that email didn't make it to the list either
>> ---
>>
>> Hi,
>>
>>
>> Back in August I picked up a Lisa 2/10 off ebay that had a bad widget that I was able to repair that one by swapping boards. I was able to get that drive working and recover a rare version of Lotus Jazz 1.0 off MacWorks, which is now on Macintosh Garden.
>>
>> This widget is very noisy, sounds like maybe the ball bearings were going, and it wouldn't start up originally until I ran it a long time on its side. I had to manually rotate the spindle as it was frozen hard. After running it for a few hours, it then booted up for a short while, but promptly died again, with the Lisa not being able to identify it, and it returning the same FF's for identification as the second widget that I'm trying to fix now (see below).
>>
>> Eventually I was able to swap out some boards that I bought from Vintage micros and fully recovered it. That's pretty great considering this is a 35 year old hard drive that was in a machine that's seen lots of abuse (the inside was filthy with dust bunnies, Styrofoam bits, pet hair, etc, and even saw some corrosion/rust of the back cover, but the Lisa itself works.)
>>
>>
>> More recently I picked up another dead widget, but despite swapping known good boards, as well as the large ribbon cable on the side that goes to the motherboard, it won't come up.
>>
>> This one did have a bad motor board (the moon shaped board on the bottom of the drive), which prevented the spindle motor from spinning at all.
>> Replacing that board fixed the spindle which now spins and unlike the first Widget, this one is quieter, however I've not been able to get it to unclamp the brake solenoid by replacing the boards and the wide ribbon cable between the top board and the back plane motherboard, nor by replacing all the boards.
>>
>> I'm able to read a resistance off the brake solenoid after a few seconds when it settles, so I don't think the coil inside is broken or shorted, and I did adjust it with a 0.12 feeler which is the classic fix for this issue, but that doesn't work. (Since the solenoid is an electromagnet of sorts, measuring the resistance of it is a way to check for breaks or shorts, however, the initial voltage that passes through it from the VOM causes a reverse voltage to come back, hence you should wait a couple of seconds to read the resistance.)
>>
>> So I'd suspect that some other earlier check is failing before it unclamps the heads. But how do I get a better status as to what's not working?
>>
>> The voice coil can wiggle freely (by hand) when the brake solenoid is moved over a bit, and I don't hear any scraping when I rotate it, so I don't think the heads have crashed. I did the same to the now working first Widget and that one still works, so I suspect doing this is mostly safe. Most of the time I'm able to measure a bit less than 2V at the solenoid, and off the top of my head I think the resistance with a VOM shows up as 14 Ohm or maybe Kohm - I have notes somewhere if anyone cares.
>>
>>
>> I get various different errors when swapping out various boards from 81, 82, and 85 and am wondering how to debug the issue.
>>
>> Using Tom's really cool NeoWidEx app, I get a bunch of FF's for the ID of the drive, and NeoWidex just says "Not a widget" and ofc none of the functions will do anything else since it doesn't recognize it.
>>
>> When I ask NeoWidEx to show the buffer I get a block that's filled with zeros are the beginning and then FF's at the end where it should say Widget-10 for the name on identity block at sector 00ffffff.
>>
>> Anyone know which board returns status to the Lisa - that is where are these 00's and FF's coming from? Is it the top controller or the motherboard?
>>
>> Also I'm wondering, what does "Drive can't keep up" mean? Is it a motor speed issue?(error 85) or is it a communication issue, and what else might cause the widget to fail to identify itself and only return 00's and FF's?
>>
>>
>> I notice there is a cylindrical sensor next to the drive spindle that's screwed in and points to the edge of the spindle; looks like maybe a hall effect or maybe an LED, with a connector that goes to the motherboard (the vertically mounted board on the back of the Widget) but I'm not sure exactly what it is and what a replacement part would be.
>>
>> It looks like this sensor is something that needs factory calibration, as there's two screws and some wax on the screws, so I'm not yet willing to taking it apart just yet incase there's something else I might be able to do first to fix the drive, and potentially recover data from it. (The drive spindle has a bunch of little dents on its outer edge evenly placed and one location where there are about 8 notches close to each other - I'm guessing these are used
>> to identify hard sectoring of the platters, and I'd guess that if I misalign this sensor it won't quite know where to locate the sector data on the platters, so if I mess with it, it will likely need a low level format and any interesting data on this drive will be non-recoverable.
>>
>> Thanks.
>>
>> --
> --
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-- 
Jason Perkins
313 355 0085

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