NorthStar Horizon Case Cover Replacements

[Allison]

>
>Subject: RE: NorthStar Horizon Case Cover Replacements
>   From: "Chuck Guzis" <cclist at sydex.com>
>   Date: Thu, 21 Jun 2007 08:56:48 -0700
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>Orientation of the drive with respect to the power transformer on the 
>Integrand was important.  Changing the position by 90 degrees offered 
>a substantial improvement, but that wasn't an option, as the panel 
>was delivered pre-cut for a drive.
>
>On 21 Jun 2007 at 7:08, Allison wrote:
>
>> I have an NS* Advantage and they also apparently did it right as the drives
>> behave well without steel shield plates.
>
>It could be that some drives are more sensitive to this sort of thing 
>than others--and that some monitors orient components in exactly the 
>wrong way.  In the case of the Durango, the monitor was a small 9" 
>Ball Brothers OEM model and the drives were Micropolis 100 TPI 
>models.
>
>The large carriage stepper motor on the integrated printer was less 
>than an inch away from the B: drive.  Another reason to shield 
>things.

;) there were a lot of design goofs out there.

Actually the worst flub is the external drive setups with power 
supplies independent of the main box. I think there may have been
three FDC cards made that suppressed WE/ if the power failed.  If 
there was a disk in the drive.. wave byebye as it did a motor on,
head load and write "1" to all drives.

>Most "PC" boxes from the 1970's had some sort of basic design 
>problem; EMI radition being only one of them (Did the Horizon pass 
>VDE certification?).  Most couldn't withstand a hipot attack; very 
>few could survive a thermal stress or shake table session without 
>having a component with "flying leads" dismount, or having cards pop 
>out of the backplane connectors.

Most S100 crates could not pass VDE or a serious hipot attack. 
Don't know if the Horizon did or did not as it predated most 
of those certifications and likely was grandfathered in like 
many.   Vibration testing, "ya gotta be kiddin", as there isn't 
a card restraint in 99% of the crates..  Some like the pre-B 
Altairs flexed so much  if lifted by opposing corners the cards 
would pop out unless they had a one peice mother board.


Allison


>
>Cheers,
>Chuck
>
>