do I really need a router for wireless?

[vaporware]

can i just connect my cable modem into a wireless access point and use one pc to share the internet connection and the ap to share?
files on multiple computers?

 

[JackMDS]

Wireless A/P is a Hub without wires; any rule that applies to a Hub will apply to A/P.

Your cable system probably will not work directly to the A/P, because it will not authenticate.

You need some form of Routing to share Internet.

Basic Options for Internet Connection Sharing

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