These Hayes modems were very specifically not winmodems, they were fully discrete modems. Winmodems typically did not use Hayes commands at all, although driver

These Hayes modems were very specifically not winmodems, they were fully discrete modems. Winmodems typically did not use Hayes commands at all, although drivers often provided support for them running on the host. This makes sense if you think about it - in a winmodem, modulation is performed by the host, so the only thing sent to the modem is commanding and never data.