The NE558 Quad Timers are monolithic timing devices which can be used to produce FOUR independent timing functions.The NE558 Quad timer has been out of production for a long time and the ones still out there are ancient stock and very failure prone.
This is a brand new Drop in DIP replacement for the NE558 Quad TImer chip.
Guaranteed to work and last a very long time.This IC was used on alot of vintage electronics and computers.
The Apple II and II plus computers released in the 1970s for instance used this IC to control paddles and joysticks. If you have issues with such things you probably have a blown NE558.