how much power from a usb1.1 port

[5ash (Philip)]

I have a 3yr old compaq presario 2200 with a pcmcia twin usb2 card powered by one of two usb1 ports on the computer. I am running a Tevion usb2 video capture device from one of the pcmcia cards usb2 ports and suspect i might be close to the power output of the port.I have succesfully used this setup with my gstar-x video camera and found the computer capture program to lock up occasionally. Does any one know how much current the usb1 port on the computer is capable of supplying.I have just aquired a belkin hi speed usb2 video capture device which runs at a maximum of 240ma and i am worried that i might overload the pcmcia card.(The belkin device works ok on my desktop machine) If anyone can provide me with some info i'd be grateful.
regards philip

[Kal (Andrew)]

From Wiki it looks like 500mA max for a single port

The USB specification provides a 5 V (volts) supply on a single wire from which connected USB devices may draw power. The specification provides for no more than 5.25 V and no less than 4.75 V (5 V±5%) between the positive and negative bus power lines.[9] Initially, a device is only allowed to draw 100 mA. It may request more current from the upstream device in units of 2 mA up to a maximum of 500 mA.
If a bus-powered hub is used, the devices downstream may only use a total of four units — 400 mA (i.e. 2 watts) — of current. This limits compliant bus-powered hubs to 4 ports. The host operating system typically keeps track of the power requirements of the USB network and may warn the computer's operator when a given segment requires more power than is available.

The PCMCIA slot itself is specified to have 500mA provided as well, so with the combined power of the PCMCIA slot and the usb1 port power, you should have enough to power two usb2 ports up to the maximum of 500mA each.

[5ash (Philip)]

thanks Kal just the info i needed .
regards philip