timing diagrams

drawtime

This is kinda a cool app that runs on ubuntu to draw timing diagrams as follows:
Example(from the drawtime website):

CS1 = 1, OE = 1, ADDR = X, DATA = Z.

CS1 = 0, OE = 0, ADDR = "".
OE -tOE> DATA = "";
CS1 -tCS1> DATA;
ADDR -tACC> DATA.

OE = 1, CS1 = 1, ADDR = X.
CS1 -tH> DATA = Z;
OE -tH> DATA;
ADDR -tH> DATA.
and you can now generate all those cool waveforms without having to worry about did you get the lines right etc..

more such cool stuff here