1.) Pulse Wave
The NCR 8496 is a PSG designed by NCR Corporation. It features 3 square wave channels and 1 noise channel. The noise channel can switch between two modes to synthesize periodic or white noise. The NCR 8496 is one of the three different chips compatible with the 3 Voice Chipset and used in the Tandy 3 Voice protocol.
The NCR 8496 was designed to mimic the functionality of the widely popular SN76496 made by Texas Instruments, as both chips have the same 3 square wave channels and a noise channel. The NCR 8496 uses a different process than the SN76496 to generate noise channel, but non-discerning ears can't tell the difference. The chips also have a different pin out.
The only system capable of playing video games to use the NCR 8496 appears to be a few Tandy 1000 computer models, the EX, HX, and TX. MAME's database doesn't list any arcade games using an NCR 8496, though, it's possible the database maintainers just grouped it with the SN76496 due to their similarities.
|Tandy 1000 TX Manual Excerpt||Download - (info)|
DOSBox emulates the SN76496, which is similar enough to this chip to play all the same games. However, it doesn't emulate the noise channel accurately since the two chips share the same code.