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mariosMSX
6th March 2015, 18:04
Hello,
i would like to ask that question, is it possible to use an A500 PSU (without mod) with the C128 ?
the A500 PSU gives 5V, 12V, -12V, while the c128 PSU gives, 5V, 9V, but i think that the c64/c128 motherboard works only with the 5V, so in theory there is no problem.
What is the use of the 9V of the c128 PSU ?

roy_bates
6th March 2015, 19:08
quick answer as its obvious to me,is no.

dont even try it,

SkydivinGirl
6th March 2015, 20:23
The 9VAC is used in the SID chip and for other parts of the C64/C128. You will certainly fry something if you just plug an A500 PSU in then turn it on. A C64 with only 5V but parts of the system simply won't work. Using an adapter, you can use a C128 power supply to power a C64.

Heather

mariosMSX
7th March 2015, 09:18
Thanx,
i will modify a C64 PSU to use.

SkydivinGirl
7th March 2015, 13:50
You should look at the amp requirements of the C128 because I don't think most C64 power supplies have enough amps to run a C128. In addition, C64 power supplies can fail and provide too much voltage on the 5VDC line, burning out chips in the system. It's best to find an actual C128 power supply.

Good luck,

Heather

rootboy
7th March 2015, 14:33
And isn't the 9 volt supply AC? I believe so...

roy_bates
7th March 2015, 14:59
And isn't the 9 volt supply AC? I believe so...



yes it is at 1 amp normally,its rectified and smoothed first(its actually closer to 10 volts ac),depending on which machine its used for its then regulated to 12 volts/9 volts and/or 5 volts dc to be used on certain ics.
most of the logic in these as we know is 5 volts.supplied by the 5 volt dc side of the supply.