Multibus ST-506/QIC-02 (was: Re: SGI IRIS 1400 ...)

From: Tothwolf <>
Date: Fri Jul 26 21:24:00 2002

On Thu, 25 Jul 2002, Tony Duell wrote:

> What I meant was that there are a dozen or more op-amps in the servo
> circuitry. All much the same (sections of 4558s or similar). And what I
> can't tell you is which of the dozen-or-more output pins you should clip
> the 'scope onto.

Which type of op-amp does your V150 drive use?

> Are there not dealers in old manuals (or copies of same) in the States?
> In the UK we have Mauritron who I would proably try first.

There are a couple of commercial outfits that I'm aware of, but they
charge $$$ for just photocopies. Maybe someone else here on the list knows
of a better place to get them.

> At least on the V150 there's a way of making up a kludgecable to connect
> the end of the head flexiprint to the servo input connector and to power
> lines. Then you can fold back the 'outer' board and still run the drive.

I think I can do something similar with this one. I may end up having to
make more than one cable though.

> Just out of curiousity, what does it do if powered up with the head
> flexipring unplugged? Any difference _at all_?

It seems to act exactly the same. It certainly sounds different when I
disconnect the servo connector though, so the head is at least trying to
load. I don't hear it actually load though, so it may indeed be stuck. I
think the V170 probably does have a head solenoid lock sealed inside the
HDA, since it has a cable that would appear to power one. I'm wondering if
the servo voltages are somewhat high because the microcontroller isn't
able the swing the head in either direction...

Seems like it might be time to open up the HDA...

Received on Fri Jul 26 2002 - 21:24:00 BST

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