But now pinball is a game of high-tech thumper bumpers, modular plug-in boards and stereo sound effects.

This approach is intended to make the standard more robust by avoiding twisted pins on the backplane: If a pin fails, only the plug-in board must be exchanged.

The 1050 Enhancement was also a plug-in board, and could be installed without soldering or permanent modification.

Presets may be expanded through up to three plug-in boards allowing a bank of 64 presets for each plug-in slot.

The S90 can be expanded through plug-in boards at three plug-in slots, thus providing additional presets, polyphony, effects and synthesizer functionality.

I.B.M. has compressed circuitry that took multiple plug-in boards on the older PC's into fewer than 100 chips.

Product offerings include integrated systems solutions, instruments, and personal computer (PC) plug-in boards that can be used as system components or as stand-alone solutions.

Each finger at the back of the board was not a mere trace on the circuit board, as usual in plug-in boards, but a leaf spring, for greater reliability.

The Compaq Advanced Graphics System consists of a plug-in board ($1,499) and a high-resolution 16-inch monitor ($1,999).

"The same thing happened with Ethernet cards," he recalled, referring to the plug-in boards that connect desktop computers to wired networks.