Convert a Commodore 64 from NTSC to PAL format

If you’ve ever used a NTSC Commodore 64 for any length of time, you’ll quickly find out that many games and demos you try to run on your machine sometimes exhibit strange graphic or sound glitches or just refuse to run properly at all. It’s most likely because the program you’re trying to run was originally written on a PAL machine. With it’s different VIC-II chip generating a different master clock signal, the PAL C64 has a few more cycles available per frame than the it’s NTSC counterpart. Tightly coded loops in programs rely on a certain number of cycles to be available. And when they’re not, well, it doesn’t work as intended.

If you happen to own a C64 “short board” system, you can convert your NTSC machine to a PAL one easy. If you are unsure which board you have inside, you can open it up and take a look or make an educated guess by reading this site. A SID 8580 is usually a good sign you have a short board. But please make sure you confirm your board type before you begin. The VIC-II types (65xx vs 85xx) are not interchangeable!

Once you’ve determined you have a short board C64, gather these two parts.

  1. MOS/CSG 8565 VIC-II PAL Chip (eBay, $23)
  2. 17.734475MHz crystal (Mouser.com, <$1)

A C64 short board, showing NTSC specific components (circled).

A C64 short board, showing NTSC specific components (circled).


Steps to conversion:

  1. Replace the existing VIC-II (8562 NTSC) chip with the new (8565 PAL) chip. You’ll most likely find the existing VIC-II chip to be socketed on the motherboard so removal will be very quick and easy with a small flat head screw driver.
  2. Replace the existing crystal. You’ll notice the old crystal is rather large compared to the new one. It’s fine, you’re just benefiting for 30+ years of innovation to make parts smaller now. De-solder the old crystal or clip the legs and remove each leg. Solder in the new crystal– polarity doesn’t matter. You don’t need to worry about replacing the old crystal’s wire “belt” that went over it.
  3. Solder across “J3” on the motherboard next to the VIC-II (it’s labeled OPEN: NTSC, SHORT: PAL).

A C64 short board, showing PAL specific components (circled) converted from NTSC.

A C64 short board, showing PAL specific components (circled) converted from NTSC.


That’s it. Now, you’ll need a display that’s capable of working with a PAL signal. A NTSC 1702 monitor will probably only show a black and white PAL image. Your easiest solution is to use a LCD monitor that has composite or s-video inputs. Most modern LCD displays are “world displays” and will support NTSC and PAL signals. Unsure? Check your manual or just test it. If you are keen on staying on the CRT route, check out Sony PVM “studio” monitors as some of those models supported NTSC and PAL.

And forget about using the RF out as the channel positions are different (but you weren’t going to use that anyway, right?).

Enjoy the brand new world of European games and demos!

4 thoughts on “Convert a Commodore 64 from NTSC to PAL format

  1. Permalink  ⋅ Reply

    Mattew

    April 11, 2017 at 3:32pm

    Does the length of the lines on the jumpers, chip, or crystal matter? could I make quick-swap cartridges to go back and forth between PAL and NTSC by running crystal, jumper, and chip to a connector that changes all of them at once?

  2. Permalink  ⋅ Reply

    Morthahna

    August 8, 2017 at 9:08am

    “A NTSC 1702 monitor will probably only show a black and white PAL image.” … Is this for certain? Somebody tried it yet? Should have thought about that before I ordered a 1702 from US currently shipping to Australia (doh)…

    • Permalink  ⋅ Reply

      paulrickards

      August 8, 2017 at 8:06pm

      Yes, confirmed it with my own PAL C64 and NTSC 1702. Of course, your mileage may vary. The horizontal frequencies is close enough to show a black and white image. The color frequencies are not close enough to work.

Leave a Reply

Your email will not be published. Name and Email fields are required.