Re: 9VAC from 5VDC?

From: Gerrit Heitsch <>
Date: Mon, 16 Sep 2013 18:25:40 +0200
Message-ID: <>
On 09/16/2013 06:16 PM, wrote:
> On 2013-09-16, at 16:53, Gerrit Heitsch wrote:
>>> My main question on that transformer is the specs show it as 500mA
>>> Current output (Max).  Since the C64 might need 1A @ 9VAC, is that a
>>> concern?
>> It depends on the C64... The last board (250469, with the large PLA) uses less than 200mA on 9V AC. The older boards need about 600mA on 9V AC. This means just the computer, nothing else (like something attached to the user port for example).
> That's exactly the main question - what amps /should/ be supplied to the USER PORT. From your measurements I take it should be not less than 0.4A, right?

The User's manual for the C64 lists 9V AC at the user port with the note 
'max. 100mA' and the newer boards have rather thin traces for the 9V AC.

So assume 200mA to be on the safe side and the 500mA transformer will be 
enough if used with a 250469 board. For the older boards you will need a 
stronger one.


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Received on 2013-09-16 17:01:35

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