50/60 Hz modifications are quite simple hacks that have been figured out for almost all Philips CD-i player types with SCART connector. But what about all the CD-i players that do not have an RGB output, either because of reduced cost or because they have been sold outside of Europe? Technically, they can still be modified, but the foreign mode is pretty useless and results in a black and white picture or no picture at all.

The reason is easily explained: All Philips CD-i players have a main system clock at either 30,0000 MHz (PAL) or 30,2098 MHz (NTSC) and additional clock generators for some components. All newer players (Mono III and up) have a Brooktree video encoder and generate the colour subcarrier frequencies (PAL 4,4336 MHz and NTSC 3,5795 MHz) from the system clock. The older players with a Sony video encoder use one or two additional crystals and some more components for this task.

Some time ago, I noticed that the service manuals of most Mono II – IV boards have notes about 8 and 32 KB NVRAM types, to be set by jumpers and resistors. I never attempted to do that upgrade because most of my CD-i players feature 32 KB NVRAM or have older mainboards that cannot be upgraded. When I mentioned the possibility in this article, CD-i Fan warned me about the consequences: If device driver and descriptor in the ROM don’t support the extra RAM, then the player might not recognize it and lose the real-time clock – or it won’t work at all.

Why would you want to upgrade the NVRAM anyways?
For example, the save files of The 7th Guest, Lost Eden and Burn:Cycle already take up a lot of space. Add some more games and settings, and you will soon reach the critical limit of 97-98% where the player refuses to start.