On Sun, Jun 17, 2018 at 11:44 PM Jonathan Gevaryahu via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
There is one "Gotcha" to be aware of if driving a PAL c64 from an NTSC psu in the USA: Because the 9VAC input to the c64 is derived from a linear power transformer, the TOD "RTC" interrupt to one of the CIA chips will be at 60hz, not 50hz, so any software which depends on that "clock" circuit incrementing at 50hz will be wrong.
On 6/17/2018 10:21 PM, Bill Loguidice via vcf-midatlantic wrote:
I use an American power supply on my PAL C-64. No issues. Same thing on the Atari 8-bit side.
As long as everything south of the step up/down transformer is consistent (all PAL or all NTSC) you'll be fine. Otherwise yes you'll have to replace the crystal and the VIC II chip if you want to use a NTSC monitor plugged into a regular NorthAmerican plug, with a PAL machine plugged into a step down transformer. In the case of my P500 exhibit at VCF whatever I replaced the crystal and VIC-II chips so I could use any display plugged into a standard socket. Oh and remember you'll need a PAL 1541 disk drive also attached to the step down transformer drives are also incompatible b