Circuit diagram for wave generator

The circuit shown produces a pretty good square wave (10 V peak-to-peak) able to drive a low impedance load, and a slightly curved triangle wave of lower amplitude, and only able to drive a high impedance load.

The 555 "timer" chip in the figure is shown with its pins in the actual DIP8 layout (pin 1 is upper left)

The time constant is on the order of T = R1 * C1