[comp.sys.atari.st.tech] Video sync disappearing with new HD?

marc@sequoia.cray.com (Marc Bouron) (03/27/91)

Hi ST-people,

I've just taken delivery of a 106Mb drive from Third Coast Technologies.  It's
a Toshiba mechanism (apparently) and came with all the usual ICD software.
Well, the drive is just fine :-)  I've got ACRES of space to play with :-)
B*U*T, it would appear that very occasionally the video is losing sync (i.e.
the picture goes apeshit and completely unreadable) :-(

This has happened a couple of times, and twice when in the middle of a multiple
file copy!!  :-o  Thankfully, the ST and HD continued talking long enough for 
the data to get through :-)

So, has anyone out there experienced such a problem when they attached a new
HD?  I've checked the obvious (cables and connections..) but nothing else is
apparent - only the fact that there is a new piece of kit hanging off the back
of the ST (520 with 2.5Mb).

Any help or clues would be greatly appreciated.  Cheers!


[M][a][r][c]


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boyd@nu.cs.fsu.edu (Mickey Boyd) (03/28/91)

In article <043439.10019@timbuk.cray.com>, marc@sequoia.cray.com (Marc Bouron) writes:
>
>I've just taken delivery of a 106Mb drive from Third Coast Technologies.  It's
>a Toshiba mechanism (apparently) and came with all the usual ICD software.
>Well, the drive is just fine :-)  I've got ACRES of space to play with :-)
>B*U*T, it would appear that very occasionally the video is losing sync (i.e.
>the picture goes apeshit and completely unreadable) :-(
>
>This has happened a couple of times, and twice when in the middle of a multiple
>file copy!!  :-o  Thankfully, the ST and HD continued talking long enough for 
>the data to get through :-)
>

Hmmm, how do I get this added to the FAQ for c.s.a.st?  Ok, I had this problem
also, and called ICD.  They were quite familiar with it.  They upgraded their
DMA cable (that which connects the computer to the host adaptor) to a nice 
snazzy one with little thumbscrews and the ICD logo printed on it.
Unfortunately, with SOME machines (apparently only some Mega's) the new 
sexy cable also causes the loss of sync that you experienced.  ICD will send 
you a new cable for FREE (they ask that you send the old one back) and your
problem will disappear (but you will have the old ugly cable :-) ).  You 
might wish to call the company you bought the drive from and let them know, 
so others won't have to go through this!!  See ya! 
--
    ---------------------------------+-------------------------------------
             Mickey R. Boyd          |  "Kirk to Enterprise.  All clear 
          FSU Computer Science       |      down here.  Beam down    
        Technical Support Group      |      yeoman Rand and a six-pack . ."
      email:  boyd@fsucs.cs.fsu.edu  |               
    ---------------------------------+-------------------------------------

rcd@cbnewsj.att.com (rana.c.dutt) (03/28/91)

In article <043439.10019@timbuk.cray.com>, marc@sequoia.cray.com (Marc Bouron) writes:
> I've just taken delivery of a 106Mb drive from Third Coast Technologies.  It's
> a Toshiba mechanism (apparently) and came with all the usual ICD software.
> Well, the drive is just fine :-)  I've got ACRES of space to play with :-)
> B*U*T, it would appear that very occasionally the video is losing sync (i.e.
> the picture goes apeshit and completely unreadable) :-(
> 

This is the same problem I wrote about earlier in this newsgroup.

It's a known ICD host adaptor problem. Certain DMA accesses or
electrical noise to the ICD HD will screw up the video refresh
logic, resulting in screen image corruption.

The solution is to solder a 22 pF capacitor to pins 12 and 13 of
the DMA IN connector on the host adaptor board.

Rana Dutt
rcd@mtqua.att.com

Roger.Sheppard@bbs.actrix.gen.nz (03/28/91)

Distribution:world 

In article <043439.10019@timbuk.cray.com> marc@sequoia.cray.com (Marc Bouron) writes:
> 
> So, has anyone out there experienced such a problem when they attached a new
> HD?  I've checked the obvious (cables and connections..) but nothing else is
> apparent - only the fact that there is a new piece of kit hanging off the back
> of the ST (520 with 2.5Mb).
> 
> Any help or clues would be greatly appreciated.  Cheers!
> 
> 
> [M][a][r][c]
> 
> 
> ################################################################################
> #                           #  marc@sequoia.cray.com           #     .   .     #
> #  Marc CR Bouron           #  M.Bouron@cray.co.uk     (ARPA)  #    _|\ /|_    #
> #  Cray Research (UK) Ltd.  #  M.Bouron@crayuk.uucp  (DOMAIN)  #   (_|_V_|_)   #
> #  +44 344 485971 x2208     #  M.Bouron@uk.co.cray    (JANET)  #     |   |     #
> #                           #  ...!ukc!crayuk!M.Bouron (UUCP)  #               #
> ################################################################################


There is a Mod for this by ICD, they fit a small Cap to the Reset line
in the Host Adaptor, I think that this info has been posted befor
but I can't remember the Cap size...
-- 
Roger W. Sheppard   85 Donovan Rd, Kapiti New Zealand...