hi kai,

thanks for the scathing attack on my inability to express my need (i will try not to repeat the same mistake again) and for the invaluable advice.

i guess lack of detail resulted in this megamess. my mistake.

I do know that a pull up is not required for memory operations!! (give me a break, i am not that bad)


I was using a 4k7 pullup (with TTL load) on port 0 and had no clue as to why i was using 4k7. Also to light a bicolor LED via port0 i was using a 1k pullup (Trial and error method of determination used here!!) So i was trying to figure out a logical method to calculate the pull up. (The picture is very clear now).

I am truly sorry for the goofup and the resulting waste of time.

About stray capacitance (Another naive question from an Electronics Student!!)

I will have to consider the pin capcitance of the microcontroller and the load, but what about the copper tracks on the PCB? What if we use a general purpose board + wires (or a bread board) do the stray capacitance calculations differ now?

thanks and sorry,

sushil