OK, I hope you still want to to test and write a bit more about this ALS120, despite the bad first impression.
I read somewhere that the earlier ALS007 does not implement 16 bit high DMA 5/6/7, even though that one should be SB16 compatible as well. Creative SB16 Waveffects does not implement high DMA either.
ALS007 - According to linux driver documentation 'als007-quickguide' it does not support high DMAs.
ALS100 - According to official documentation 'S100DM2' it supports the high DMAs!?
ALS120 - According to official documentation 'ALS120DM' it does not support high DMAs.
ALS200 - According to official documentation 'ALS200DM' it does not support high DMAs.
Then how is 16-bit sound transferred:
B. Masta 14 Jul 1999: You can definitely send 16-bit data over an 8-bit channel... it just goes as 2 separate transfers per sample. This is fully documented in Creative's SDK, CTSBHWPG.EXE (686 K). This document doesn't cover the CT417x models (ViBRA and WavEffects) specifically, but they are the same in this respect. (The big difference is that they can do 16-16 full-duplex, which the other Creative ISA cards can't... but there is a propietary trick to enable it. Developers have to sign a non-disclosure agreement.)
Where we find:
On Sound Blaster 16, 16-bit sound data is usually transfer through 16-bit DMA channel (specifies on the "Hh" parameter of BLASTER environment variable). However, the hardware also supports transfer 16-bit sound data via 8-bit DMA channel. To make this possible, the program SBCONFIG.EXE come with Sound Blaster 16 package must be run to configure the Sound Blaster 16 appropriately. When SBCONFIG is run, the BLASTER environment entries "Dd" and "Hh" must be set such that d and h are the same 8-bit DMA channel number.
SBCONFIG should be similar to the well known DIAGNOSE program for SB16's.