Gianmario.Scotti_at_nokia.com
Date: 2004-01-10 16:52:08
Wow, that looks like a brick of epoxy! Umm... so it's not the "guitar pedal"-type C-64 PSU.
What I meant by reverse-engineering, is: what "signals" it gives on the "output" and make a circuit that does the same. You don't need to know how it's made. If I understand correctly, it gives 9V AC and 5V DC regulated, right? First question that pops to mind: why didn't CBM simply make a PSU that contains a transformer and nothing more, which would give 9V AC, and then the rectification and regulation (to obtain 5V DC) would be done inside the C-64 ? Just look at how the C-16/C-116 is done. (actualy, there the PSU contains a transformer AND a diode bridge+electrolite capacitor, to rectify (but not regulate, yet) the AC to DC).
Anyway, supposing a temporary engineering brainbarf on part of CBM, the PSU to make would be fairly simple, really. Check the ACCEL Schematic I attached here.
> -----Original Message-----
> From: owner-cbm-hackers@cling.gu.se
> [mailto:owner-cbm-hackers@cling.gu.se]On Behalf Of ext Ryan Underwood
> Sent: 10 January, 2004 14:26
> To: cbm-hackers@cling.gu.se
> Subject: Re: C64 power supply replacement
>
>
> On Sat, Jan 10, 2004 at 03:33:13AM +0200,
> Gianmario.Scotti@nokia.com wrote:
> > Hey Ryan,
> >
> >
> > sorry to hear about your problems with the PSU.
> > However, could you tell me more about this "Pinto" power supply?
> > How does it blow up your C-64, exactly?
>
> I read on comp.sys.cbm archives that this power supply used a
> rectifier
> to cut the 9V down to 5V, and eventually due to heat/age, the
> regulator would short and you would end up with 9V on the 5V output,
> which isn't too nice to the C64 logic...
>
> > And, do you have pictures of this PSU, so I can be sure
> which exactly you mean?
>
> Yeah, see here:
> http://home.icequake.net/~nemesis/misc/c64-psu1.jpg
> http://home.icequake.net/~nemesis/misc/c64-psu2.jpg
>
> This is after cracking the shell off and trying to chip some of the
> epoxy off -- you can see a heat/ground plate exposed on the right side
> of the picture.
>
> > I think it's simple to reverse engineer the PSU.
>
> I would think so too, if I had a way of getting rid of this brick of
> epoxy without destroying the circuit....
>
> --
> Ryan Underwood, <nemesis@icequake.net>
>
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