| This page currently consists of an excerpt from pages 161-162 of Commodore 64 Troubleshooting & Repair Guide by Robert C. Brenner (SAMS). Please note that the components discussed here refer to Rev. A motherboards and your mobo may be laid-out differently. I would like to add more details from other sources as I run into them. If you have experiences converting C-64s between PAL and NTSC I'd love to share them here. I'm also interested in details about fixing PAL programs for NTSC. Please email your anecdotes and ideas to profdredd@yahoo.com |
Commodore 64 computers purchased in the United States are configured for the 525-line, 30-picture-per-second NTSC (National Television System Committee) video standard. For those of you living in, or moving to, countries where the European 625-line, 25-picture-per-second PAL (Phase Alternate Line) video standard is used, you must convert your NTSC-configured Commodore 64 to PAL video. You must also make sure you have the correct power converter installed, if necessary. This section covers conversion of your video from NTSC to PAL.
As shown in Table A-2, many of your motherboard components are different depending on which type video display you're driving:
| Component | NTSC | PAL |
|---|---|---|
| C70 capacitor | 16 pF +/- 5% N2200 | 15 pF +/- 5% N3300 |
| R52 resistor | 680 ohm 1/4 W, 5% | 330 ohm 1/4 W, 5% |
| R53 resistor | 910 ohm 1/4 W, 5% | 100 ohm 1/4 W, 5% |
| U4 2364A ROM | 2364A KERNAL JIS | 2364A KERNAL US PAL |
| U5 2332 ROM | 2332B char gen JIS | 2332 char gen US PAL |
| U17 PLA | 82s100N/7700 JIS, NTSC | 93459 PLA |
| U19 VIC | 6567 NTSC | 6569 PAL |
| Y1 x-stal | 14.31818 MHz | 17.73447 MHz |
Located between the RF modulator can and the video can on the motherboard is the sound carrier select jumper. With this jumper in place (shorted), the system is set for what Commodore calls "G. PAL video". Cutting this connection (open) sets up the board for "I. PAL" as shown in Fig. A-7:
( ) (-) I.PAL G.PAL |
Inside the video can and off the upper right corner of the VIC chip is a set of eight holes, in two rows of four. These are the jumper holes for NTSC/PAL video. The correct position for the jumper, depending on the video display you intend to drive, is shown in Fig. A-8:
E3 E2 o o o o I I o o o o E1 PAL (NTSC) (PAL) |