I searched for this one a looong time! Let's see what the Aztech Support wrote
You will find the most recent drivers for this card in the /pub/SG/sc16
folder of ftp.aztech.com.sg
This card will not satisfy the requirements of win2000, no drivers will be
written for it.
You will have to check the barcode on the back of the card itself to
determine if it the SC16-3D or the SC16-3D(W) card.
For AZT1022 (SC16-3D), download SC163DW.ZIP
For ADS7181 (SC16-3D), download SC163D.ZIP.
For AD1816A (sc16-3d without eeprom), download SC163D.ZIP.[...]
So I had the SC16-3D(W) card which does not work with the SC16-3D drivers. The driver I uploaded is the one for the (W) version, which was often integrated in computers of big assembling corporations like IBM.