The WiFi232 is a traditional old-timey old-schooley Hayes-compatible 300-115200 baud modem, no wider than its own parallel DB25 port.
Automatically responds with a customizable busy message when already in a call.
The killer app seems to be using it to get internet onto ancient retro portables like the TRS-80 Model 102, but it's been put through its paces on various 16-bit Commodores, Ataris and Apples too. Here's Blake Patterson:
https://www.youtube.com/watch?v=92RIT_L-8jA
The purpose of the device is to act as a bridge between your serial port and your local WiFi router. It has a 25-pin RS-232 data interface and a Mini-USB connector for power — it should work with any computer sporting a standard serial port.
The WiFi232 is configured by connecting to the device's built-in web server and loading the configuration page or by issuing extended AT configuration commands. For example,
AT$SSID=MyWifiHotspotName
points the device to your WiFi hotspot. Once things are configured (it supports 300 to 115,200 baud), just load up your favorite terminal program, type:
ATDT bbs.myfavbbs.com
and the WiFi232 "dials" into that telnet BBS. Your vintage computer thinks its talking on the phone.
It's $33 as a pile o' parts or $49 assembled, but there's a waiting list.