Hi Snajeev,

I have to dial the numbers also, so I can't use 8870 as is only receiving IC.

I have to use either 8880 or 8888.

8880 is though not compatible with 8051 but its people have used it with 8051 and it works. 8870 is not also 8051 compatible but I have used it with 8051.

Its only a matter of making ports /pins high or low and sending / receiving data according to the algorithms in the data sheet.

The incompatibilities are only due to the architecture of data/address buss. Multiplexed or non-multiplexed. If you can go around this then you can use this IC with 8051. OR you will be need some pullups on the ports.

Your advice is good that I have to be certain about either S/W or the H/W. But How ????

I have simulated the S/W on 8052 simulator and it wokrs according to the algorithm in data sheet.

Login analyzer I don't have (thogh you asked not to say so, but sorry).

BOTTOM LINE:
==========

I am still stranded with the problem and my MT8880 is not yet showing the correct data received. I only have to change my design with other chips. (potato chips)


Simon