There were a few Intel drivers, but none that matched the Intel 21140 adapter. After looking thru system information screens, I saw it detected a DEC 21140 FasterNet chip and began looking for a similar driver. There's one for DEC Tulip (driver name is 'tulip'). I left the 'Parameters' prompt blank and it installed.
So I'm at the Installation Settings screen, but the Software section reads, "Cannot read package data from installation media. Media error?" in red letters. It knows I'm installing via FTP and am connected to the FTP server (I connected with a separate FTP client on another box on network to make sure connection was good). What gives?