There are two programs on the 1bit.dsk
SLTON.BIN assembled from slton.asm with lwasm with a listing in slton.lst 
This program appears on page 278 of the Assembly Language Programming for the Color Computer (1985) (Laurence A Tepolt).pdf file.
Block at $4000 (16384) of length $003A (   58): end at $403A
BIN file length: $0044 (   68)
Entry point    : $4000 (16384)
Content length : $003A (   58)
Overhead       :  17.2 %
Single continuous block goes from $4000 (16384) to $403A (16442)



P25.BIN: assembled from P25.ASM with lwasm with a listing in P25.lst this program appears as program 25 in the 6809_ch14_15.pdf file.
Block at $3E00 (15872) of length $0124 (  292): end at $3F24
BIN file length: $012E (  302)
Entry point    : $3E00 (15872)
Content length : $0124 (  292)
Overhead       :   3.4 %
Single continuous block goes from $3E00 (15872) to $3F24 (16164)


On MAME these two programs are totally silent. On xroar and presumably on a real coco they both produce sound.
I think somehow the 1bit dac is not being routed properly somehow. 
