[GanjaTron]

Hi everyone,

while replacing the dead batteries in my Crimson's DS1216B NVRAM with an external CR2032, I started getting progressively weirder issues with the Reality Engine such as (see attachments):

• The PROM console sporadically complained about an invalid EEPROM or failure to open the graphics console gfx(0)
  
• An MP bus error right after booting (never had that before!)
  
• Corrupt graphics when the console did occasionally initialise.
  

After swapping the DG2 with a spare, I got a sane picture again, so I'm wondering what happened. Has anybody seen something like this, and where exactly is the mentioned EEPROM located, and what does it contain?

The DG2 has only one socketed chip, and it's an 8-pin Xilinx 1765DPC PROM which stores the FPGA configuration. The VPP and VCC supplies are tied together, so the chip is hardwired for read-only operation, and must be externally programmed, which doesn't make it an EEPROM. Is anyone familiar with this chip and what happens if the contents are corrupt? Or should I be looking elsewhere?

Thanks for any infos, really scratching my head over this one (again).
Damn, these things are high maintenance! 

--Roland