I have been tring to use the EEPROM built into the ED2.
I know you have to set EECON(0xd2) to 0x02 to switch the movx command over to EEPROM.
here is the latest incarnation of my code:
I use SDCC and 'byte_read' is a global variable.
//******************************************************************
//* Write EEPROM
//******************************************************************
void WriteEE(unsigned int Addr,unsigned char Data)
{
Addr;
Data;
while(EECON & 1){}; //check the EEBUSY bit
EECON=2;
_asm
mov acc,b
movx @dptr,a
_endasm;
EECON=0;
}


//******************************************************************
//* Read EEPROM
//******************************************************************
unsigned char ReadEE(unsigned int Addr)
{
Addr;
while(EECON & 1){}; //check the EEBUSY bit
EECON=2;
_asm
movx a,@dptr
mov _byte_read,a
_endasm;
EECON=0;
return byte_read;
}