Hi David,
There is a trial version of the SDK I think they got SDK 15.7 SP127 up on the site currently. This will work to ASE 16.x.
Go here: http://scn.sap.com/community/downloads
There is an article titled "The SCN Download Center is Now on the SAP Store: What's New?"
In this article there is a link to the SAP store click it
Than do a search for "SAP SDK for Adaptive Server Enterprise"
Click the free trial and it will ask for your information and send you an email.
From the link you get you should see a list of the SDKs. You want the one for Windows Server on IA32 32 bit 22941.
Thanks,
Dawn Kim