The Atom N270 laptop has three USB 2.0 ports.
There is no minimum or required number for USB ports on a laptop. Depending on the age and design of the laptop, it could be anywhere from zero to ten. I have seen only 2 USB ports on older laptops, most of the new ones atleast have 4 USB ports. Netbooks(10" & 11") have not more than 2 USB ports. If in anycase you need more USB ports, you could buy an USB hub for as less as 10$, which will add 4 more ports to your laptop.
USB ports
Well depending on what usb ports it has usb 3 ports are the best to use.
This laptop features three Hi-Speed USB and four pin USB Type A ports.
All national ports have been closed.I need more USB ports on my laptop.
You need to place the USB fan cooler beneath your laptop and connect it to one of the ports for it to cool your laptop.
You cant, its either going to be usb 1.0 or usb 2.0.
There are 4 USB 2.0 ports on this laptop. In addition, there is also a firewire (1394) port and an HDMI port.
The Sony VAIO VGN-NS130E/S, comes with 4 high speed USB ports, and 2 memory slots.
All computers vary. Any where from 0 to 10.
Yes you ccan get a memory card reader for a laptop that connects via USB ports.