How many computers can share a single Access Point ?
Many wireless access points and routers claim support for up to 255 connected devices. However, while theoretically possible, hardware specifications and wireless limitations would make the performance of such a network very poor.
Depending on the the hardware specs, manufacturer, and design of the Access Point, some support only 16 wireless clients, some 32, and others the entire subnet of ~253.
For example, 802.11b APs typically have only 4-5 Mbps throughput ( and "enhanced" ones up to ~7 Mbps ), so you may run out of bandwidth long before you run out of number of clients. On the other hand, a 802.11n access point can typically support dozens of connected computers and other devices.