Philips CDI470 32 KB NVRAM Upgrade

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.

CD-i memory full (8 KB)
CD-i memory full (8 KB)
Continue reading Philips CDI470 32 KB NVRAM Upgrade

Philips CDI470 Diagnosis and Repair

For upcoming experiments, I was in need of a working CD-i player with a Mono IV mainboard and 8 KB of NVRAM. I checked my basement and found a broken CDI470/20 that had been sitting there for years. Previous repair attempts had failed and I hadn’t bothered to look at it since.

Upon the first start, it greeted me with the memory full error:

CD-i memory full error
CD-i memory full error
Continue reading Philips CDI470 Diagnosis and Repair

NEC PC-FX Mouse (FX-MOU) Repair

When taking new screenshots for my old PC-FX articles, I noticed that my PC-FX mouse (FX-MOU) didn’t work properly anymore. It still detected the movement fine, but if failed to register one of the mouse buttons. My spare mouse turned out to suffer from this too.

It’s time for a quick repair. Two screws underneath the label hold the mouse together (marked with yellow circles).

NEC PC-FX Mouse (FX-MOU)
NEC PC-FX Mouse (FX-MOU)
Continue reading NEC PC-FX Mouse (FX-MOU) Repair

Serial Terminal on Psion Serie 5mx Pro

This is a follow-up to the Serial Terminal on Atari Portfolio article. The Portfolio with the Serial Interface add-on turned out to be too limited and bulky for being a mobile VT100 terminal, and I actually never used it. For years, I was looking for an even smaller alternative and have finally found it: The Psion Serie 5mx Pro. It is basically a Psion Series 5mx (or Ericsson MC218) for the German market. The operating system (EPOC32 Release 5) of this model is not stored in ROM, but instead it is loaded from the CF card into RAM on the first start. An English version of the operating system file (sys$rom.bin) can be found here.

Psion Serie 5mx Pro and Philips CDI470
Psion Serie 5mx Pro and Philips CDI470
Continue reading Serial Terminal on Psion Serie 5mx Pro