Hi Peter,

I was looking at your code, and I've got a question: what is MDE? Comments say SDA enable; does this mean you have a driver external to the uC that you are enabling/disabling?

Wait a minute...what 8052 variant are you using? Does it have hardware I2C? Some of your comments would seem to indicate that [setting I2CCON], but your code looks like software I2C. Your $MOD812 would suggest a ADuC812, but that doesn't have hardware I2C...

I have found that some hardware I2C implementations require more software support that a straight software implementation.

Have you looked at Atmel's website? They have an apnote there for communicating with their 24Cxx eeprom (software I2C), and have source code for I2C in asm. If you can talk to an eeprom, you will be able to talk to your RTC.

Good luck!

Dennis