There are some defunct companies (Atto etc) without any information on the web.
Officially it is said, the AHA- series can be used only on PCs. However, there is a variant AHA-2940 U2B/MAC which is quite cheap.
I bought two, and their SCSI buses were flawlessly recognized and used by the ROM of the beige G3 minitower.
Unlike the PC versions, I did not find any support or download pages for the Mac adapter.
On the PC version, one can use the BIOS or driver/utility software to see adapter settings and to configure them.
Do you know of any utilities or other ways to configure things like onboard termination on the Mac 2940?