The correct location to connect +5V and GND, can be found even by
a short look to the C64c PCB. GND occupies large areas on board
generally, especially near the power connector. I chose one of the gnd
legs of this connector to solder the ground level wire. And +5V is the
second after GND which occupies large trace areas. But we need a very
first entry to the +5V trace. So, we again look for a place near the
power connector. Actually there is a good place to solder our +5V wire.
It's one of the legs of R19 resistor, which is connected directly to the
power switch. But, we have to remember that the switch must be off always
for this connection, otherwise a short-circuit happens to the power supply.
Lastly, the +12V wire has to be connected. We need a place after the
regulator circuitry, to connect this wire. And the best place to solder
this wire, as shown in the figure_1, is the positive leg of 1000
microfarad rectifier capacitor C63.
Actually, if you want you can run your C64 with 8 AA type batteries.
Batteries must be grouped by 4, and these two groups must be connected
parallel to a +5 regulator chip. Then the output of the chip must be
connected to the C64c PCB as described above. There is enough room to put
8 AA size 1.2V rechargable batteries in the standard C64c case. To charge
these batteries you need a 9V 100mA source and 10-12 hours. Of course,
you cannot get sound with this battery solution. Instead of the AA size
batteries you can use a car battery with a proper +5V regulator also.
![[fig1: external power for
C64c]](powc64c.gif)
Powering a C64 computer with external +5V, +12V DC supply should not
confuse anybody. At first glance, we can think that C64 cannot work
without an AC 9V. If we think why AC and why 9V is needed we can find
that it is not needed in reality ;-). C64 uses AC to extract 50-60Hz.
tick for TOD clocks only. VIC doesn't require it to time the composite
video picture. Also AC nature of 9V is used to convert this 9V to 12V
with a simple coil/transformer. This 12V, after conversion to DC, is used
for powering SID. And C64 can do without a SID chip also. This 12V DC or
9V AC (depends on the version) is also connected to the user port. Thus,
if we know where to connect a +5V DC and GND to C64 we can make it work.
But if the sound is needed, we have to know where to connect the +12V DC
either.
![[fig2: PC power supply
connector]](powcord.gif)