Re: Question(s) on AST RAMSTAK Plus & AE Vulcan Hard Drive

[capknight <cepheusfilms@gmail.com>]

On Dec 9, 8:10 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
> capknight wrote:
> > Thanks for all the info on the drives. I've already tried out a few;
>
> > Seagate:
> > Model #: ST3120A - 105 megabyte
>
> > Quantum:
> > Model #: ProDrive ELS PI12A492 - 120 megabyte
>
> > No go on both of those drives.
>
> > The original drive in my Vulcan is a;
>
> > Western Digital:
> > Model #: WD93048-A - 40 megabyte
>
> It almost seems that AE wanted it to be difficult to upgrade a
> Vulcan by swapping drives--maybe because they had such a nice
> profit margin based on drive capacity, and drives have always
> been getting bigger and cheaper.  ;-)
>
> > When I connected the drive up to an external firewire chassis (for
> > power only)
> > it kicked in and was able to boot. The internal Vulcan power supply
> > only seems
> > happy enough to run the IIGS. I'll probably pull it out completely
> > when the
> > LittlePower Adapter IIGS from ReactiveMicro comes.
>
> That suggests to me that the +12v supply is the one that has
> limited capacity (though if the problem is on the "line side" of
> the supply, then only the total load matters).
>
> If you open the supply (as you have if you have access to the
> disk drive ;-), you can examine the larger electrolytic capacitors
> near the AC line end of the supply--they will be fairly high voltage,
> like 250v, and medium-large capacitance, like 100uF.
>
> These are the most likely capacitors to be causing your problem, since
> as they dry out, they lose capacitance and increase their equivalent
> series resistance, both of which make them less able to "hold up" the
> supply voltage for the high frequency switch between AC half-cycles.
>
> You don't need to remove the capacitors to "test" them.  Just bridge
> the old cap with a new one of equal or higher ratings (both capacitance
> and voltage), and if the supply works properly, then that cap needs
> replacing.  (Watch polarity carefully, use clip leads or temporarily
> soldered "flying leads" to avoid shocks, and discharge (short) the
> capacitor after powering off before getting your hands across the
> terminals.)
>
> -michael
>
> ******** Note new website URL ********
>
> NadaNet and AppleCrate II for Apple II parallel computing!
> Home page:  http://home.comcast.net/~mjmahon/
>
> "The wastebasket is our most important design
> tool--and it's seriously underused."

Definitely they were interested in protecting a profit margin! Haha..

I'm curious to see how the "Gold" ROM works in the machine. I think
it's supposed
to come today from ReactiveMicro.

I'll check the power supply out when I get more time at the end of the
month. It'll
be fun to get the Vulcan behaving properly again. I always wanted one
when they
came out and it's fun to just play with it. I've heard it's not a
terribly fast system, but
it is very cool how they were able to wedge this thing into the IIGS.

I'll drop back when I get the Vulcan card upgraded and I find some
EEPROMs for
the AST Ramstak card.

Best!

C