Sound from laptop computer
If a lap top does not come equipped with a sound card, there are two options:
Some synthesizers and other MIDI devices will connect to the serial or parallel ports on a computer. If the lap top has a free serial or parallel port, one option is to buy a synth that will connect to this port and includes the necessary MIDI driver to support it.
If the PC has a PCMCIA slot, there are sound cards available in this format.