If you are using one of the comcast issued wireless gateways the XB3 models offer 4 ethernet ports for hardwired computers and the XB6 models have 2 ethernet ports. Depending on your speedtier the wireless would have no issues supporting 8 or more devices.
Thanks - I looked at the modem and it looks like there are 4 connections but I cna't see where the model name is. I had a notice to upgrade my comcast modem so maybe I should check into that. I like to leave things alone when they are working!