I2C Problems

[Gugz]

Hi guys! I'm trying to communicate two 16f877 with I2C, but it just don't work and i have no idea why...
It seems like the master sends the address, but the slave don't recognise it... Can you help me please?
The part of the code from master that utilizes I2C and from slave are:

MASTER:

#use i2c (master, scl = pin_c3, sda = pin_c4)
(....)
i2c_start ();
i2c_write (0xA0);
delay_ms (10);
i2c_write (dado1);
delay_ms (10);
i2c_stop();

SLAVE:

#include <16F877.h>
#device adc=8
#fuses NOWDT,RC, NOPUT, NOPROTECT, BROWNOUT, LVP, NOCPD, NOWRT, NODEBUG
#use delay(clock=20000000)
#use rs232(baud=9600,parity=N, xmit=PIN_B2, rcv=PIN_B1, bits=9)
#use i2c (slave, address = 0xa0, scl = pin_c3, sda = pin_c4)

#int_SSP
SSP_isr()
{
printf ("%d", i2c_read());
}

void main ()
{
enable_interrupts(INT_SSP);
enable_interrupts(global);
while (true);
}

Oh, by the way, I'm trying to send 'dado1' to the slave and to write this in a Virtual Terminal (PROTEUS).

Thanks for the help.

[PCM programmer]

How to create a master program that will talk to the CCS example file,
Ex_Slave.c:
http://www.ccsinfo.com/forum/viewtopic.php?t=28473&start=1

Possible reasons why Proteus could have problems:
http://www.ccsinfo.com/forum/viewtopic.php?t=28744

[Guest]

MASTER:

#use i2c (master, scl = pin_c3, sda = pin_c4)
(....)
i2c_start ();
i2c_write (0xA0);
i2c_write (0x00);
delay_ms (10);
i2c_write (dado1);
delay_ms (10);
i2c_stop();

Still don't work.

[PCM programmer]

[Gugz]

Ok, I forgot the pull-ups resistors... Now it's working... But, still have some weird going on: for example, if dado1 = 52, when i make printf ("%d\r\n", dado1); , the virtual terminal shows:
-06
52

So, why this -06 is showed? Some kind of a junk?