[Coco] calling all MM/1 owners

Joel Ewy jcewy at swbell.net
Thu Jan 24 22:54:14 EST 2008


Bob Devries wrote:
> I just removed the I/O board from the MM/1 to more closely examine the
> RTC.
>
> I found that one of the termination resistors for the SCSI bus is
> oriented the opposite way to the other two. RN5, the middle one is
> different. Now I'm wondering what effect this will have on the working
> of the SCSI bus? Could this be my problem?
>
> Joel, the termination resistor's 'notch' or 'dot' end should be in the
> solder pad that's square, am I correct?
>
Yeah, that's right.  I think that's the common lead for the resistors. 
Resistors themselves aren't directional.  Does it make a difference
because of the way they're assembled in an array?

JCE
> -- 
> Regards, Bob Devries, Dalby, Queensland, Australia
>
> Isaiah 50:4 The sovereign Lord has given me
> the capacity to be his spokesman,
> so that I know how to help the weary.
>
> website: http://www.home.gil.com.au/~bdevasl
> my blog: http://bdevries.invigorated.org/
>
> ----- Original Message ----- From: "Dave R in Illinois"
> <lazyhand at sbcglobal.net>
> To: <coco at maltedmedia.com>
> Sent: Thursday, January 24, 2008 12:03 PM
> Subject: [Coco] calling all MM/1 owners
>
>
>> Have you checked to make sure the drive / cable is properly
>> terminated? I've
>> seen corroded pins on terminators do strange things to raid arrays. I
>> never
>> owned a mm1 so I am not sure if there even is one, I would assume there
>> would be.
>>
>>
>>
>> -Dave
>>
>>
>>
>> ______________________________________________________
>>
>>
>>
>> I have a small problem with my MM/1, and I'm wondering if there was
>> ever a
>> fix for it?
>>
>> When I power it up, the computer goes through its procedure to try to
>> boot
>> from the floppy, and then from the SCSI hard disc. It *always* locks
>> up the
>> SCSI bus at that point, and pressing reset does not unlock it. I need to
>> cycle the power to unlock it. It then usually fires up correctly, but
>> not
>> always.
>>
>> My MM/1 is a 3MB with the expansion board. It has a 170MB Quantum SCSI
>> drive. The drive itself initialises properly (at least, it makes all the
>> right noises).
>>
>> Comments anyone?
>> -- 
>> Regards, Bob Devries, Dalby, Queensland, Australia
>>
>> Isaiah 50:4 The sovereign Lord has given me
>> the capacity to be his spokesman,
>> so that I know how to help the weary.
>>
>>
>> -- 
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco 
>
>
> -- 
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>




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