Tandy DAC is an audio protocol used on RadioShack's Tandy 1000 SL, TL, and RL series of computers. The DAC functions in a similar manner as the Speech Thing, and with software, could even emulate the device. However, the Tandy DAC can take advantage of DMA, making it much less processor intensive. The 8-bit DAC could sample at frequencies up to 48 kHz.
The following programs emulate the Tandy DAC: