Re: Converting PAL P500 to NTSC

Re: Converting PAL P500 to NTSC

From: B Degnan <>
Date: Sun, 05 Jul 2009 17:08:45 -0400
Message-ID: <>
Ullrich von Bassewitz wrote:
> On Sun, Jul 05, 2009 at 09:47:13PM +0200, Ullrich von Bassewitz wrote:
>> I've done the opposite quite some time ago and yes, it's the same as in the
>> C64. As far as I remember, you have to replace VIC and crystal, and change a
>> jumper.
> Looking at the schematics, I see no such jumper, so it's probably just the
> first two.
> Regards
>         Uz

I swapped the VIC-II chip for the NTSC version, but not the crystal, and 
now I can at least view a black and white screen on a 1701 monitor.  
There is adequate heat-sink compound on the VIC -II.

All things considered, I do have a PAL-compatible TV with composite 
video input, and I will probably return the original PAL VIC-II chip to 
the computer and use the PAL TV.

On a related note...
The FPLA's are 906114-02 and 906114-03.  They run very hot.  Not quite 
too hot to touch, but hot enough that I should have a fan on them while 
powered on.  I am somewhat concerned about long-term use.   I am running 
a step up/down power unit to power the computer.  The voltages to the 
motherboard coming from the power supply are correct (+12V, -12V, 5V, 
2.5V), the TIP29 transistor appears to be sending the correct 
voltages.   I don't believe the power source is causing the FPLA's to 
run so hot, but I could be wrong.  The computer appears to function just 
fine other than the wrong crystal for display output.  My reason for 
using this computer is to experiment with it, but I don't want to ruin 
it either.  I have newer 906114's (-04 and -05) that I could try to see 
if it makes a difference.  The version of the BASIC ROMs are -02.



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Received on 2009-07-05 23:20:28

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