The zig-zag in-line package or ZIP was a short-lived packaging technology for integrated circuits, particularly dynamic RAM chips. It was intended as a replacement for dual in-line packaging (DIL or DIP). A ZIP is an integrated circuit encapsulated in a slab of plastic with 20 or 40 pins, measuring (for the ZIP-20 package) about 3 mm x 30 mm x 10 mm. The package's pins protrude in two rows from one of the long edges. The two rows are staggered by 1.27 mm (0.05"), giving them a zig-zag appearance, and allowing them to be spaced more closely than a rectangular grid would allow. The pins are inserted into holes in a printed circuit board, with the packages standing at right-angles to the board, allowing them to be placed closer together than DIPs of the same size. ZIPs have now been superseded by surface-mount packages such as the thin small-outline packages (TSOPs) used on single-in-line memory modules (SIMMs) and dual-in-line memory modules (DIMMs).
ZIP chips in ZIP sockets
ZIP memory devices are now only to be found in obsolete computers, some of these are:
As of 2008, some high-power devices (such as high-voltage op-amp ICs, voltage regulators, and motor driver ICs) are still being manufactured in a package with a zig-zag pinout.  These zig-zag packages include variations on the TO220 such as "TO220S", "staggered leads TO-220-11", "staggered leads TO-220-15", and HZIP. The name pentawatt or hexawatt is also used with chips like TDA2002/2003/2020/2030 and L200.