Please note all addresses given will be calculated for slot 0. Refer to a reference text to find out how to modify the address to select other slots.
$C081 READ THE ANALOG TO DIGITAL CONVERTER
$C083 ANALOG TO DIGITAL CONVERTER BUSY LINE
$C085 OUTPUT LEVEL CONTROL
$C086 WRITE TO DIGITAL TO ANALOG CONVERTER
$C087 HILOW ( 1 BIT INPUT SAMPLE )
The HILOW sample of the input audio signal can be used to output sound through the internal speaker ( with about 8 db signal to noise ratio ). Currently this feature is unsupported by software.
The A-to-D busy line need not be checked for software routines that sample the A-to-D converter at 30khz or slower. The bust line is connected to data bit 7. A LDA BC083 followed by a BRANCH IF PLUS instruction would indicate that the A-to-D was bust ( if the branch was taken.)