Operating System: Windows 95 & DOS (Note: might work with other versions of this os.)
Their driver name y95v9336.zip
This driver seems to be for all Yamaha chipset ISA cards including the 701s. If you get an error on executing the install file, it is probably due to the fact that this driver (as well as the Labway Yamaha chipset generic driver listed elsewhere here) is trying to find other Yamaha hardware. You can safely ignore the error.
The SAx file(s) that Win95 will look for may not be found in the OPLx folder that the install creates. Try to find the files Win95 needs using Find files/folders or look in your Temp folders in Windows, Program Files, etc.
If you download this from FTP site, then also download the manual(s) as well.