Hi Sanjeev,

Probably you have shifted to the room where its airconditioned...... :-)

I think you should have used 74HCT.... instead of 74LS... . The former one is capable to cope with heating, I suppose.

By the way you said that you divided the parallel I/Os into group of 3wires each and each group you wired to a slaves on the slave side of 74LS243. What about the master side of the 74LS243. On this side I think you had to tie up the like wires together and probably this where the overloading occured.

Why didn't you use standard Master/Slave serial protocol for 8051.

Anyway, stay cool

Simon