Texas Instruments TravelMate 5000 Series User Reference Manual page 158

Parameter
Dx
Ixx
Example:
n
Note: Press ESC to end recording.
RECFILE LEFT.WAV r11025 S
creates a stereo digitized audio *.WAV file with
sampling at 11 kHz (recording 22 kHz samples
per second at 8-bit)
DOS Utilities
Description
Sets the DMA channel number
for 8-bit files (1, 3, 5, or 7).
Ixx - Sets the IRQ channel
number (2, 3, 5, 7, 10, or 15).
Sound 8-7