Re: Hidden power switch for Widgets?

Thanks, folks! I'll try some of these ideas out when I get the chance...

--Tom

On Monday, January 26, 2015 at 2:06:12 PM UTC-5, PSchaefer wrote:
>
> Am Sonntag, 25. Januar 2015 20:28:27 UTC+1 schrieb Tom Stepleton:
>
> I'm not sure what would be required for that to work, but my recollection
>> is that it can't be as simple as putting a switch between some/all of the
>> power lines and the drive. I think I once tried disconnecting just the
>> power connector (and not the data ribbon cable), and the green drive LED
>> lit up anyway, even though the drive mechanism was still. If that memory is
>> accurate, some of the data cable's lines must also need to be disabled to
>> truly leave the Widget "off".
>>
> To disable the Widget you can just interrupt the motor +12V, leaving all
> other voltages connected. The selftest will be aborted in case the spindle
> does not spin up, therefore the head brake keeps engaged. However, the
> drive is still visible to the Lisa and it will wait until timeout before
> trying to boot something else.
>
> Pin 19 of the Sub-D25 connector (or the equivalent pin on the 26pin
> header) is an "open cable detect" signal. It has a pullup inside the Lisa
> and is tied to ground in the device. It may sufficient to cut this signal
> to make the drive invisible to the Lisa. Try this with the IDEfile first
> before cutting the Lisa drive harness.
>
>
> Regards
> Patrick
>
>

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