Prolific chipset

Latest Prolific USB to Serial Drivers

While not the cheapest USB to serial chipset available, the Prolific chipset is popular because of it's wide compatibility with systems and serial devices. It also supports Windows (98, ME, 2k, XP, Vista and 7), Linux and Mac OSX.

A very solid USB to Serial with the Prolific chipset will run somewhere between $10-20 depending on the cost of the housing. Sometimes they can be found for less (on ebay for instance), but be careful - lower quality adapters tend to have poor soldering which can lead to equipment damage or failure.

One of the myths floating around is that the Prolific chipset can't handle USB 2.0 ports. This isn't true at all - USB 2.0 ports work fine with the Prolific chipset - in fact, USB 2.0 is fully backward compatible with USB 1.1 so the argument is without any foundation. It is true that these adapters work at the slower USB 1.1 speed (slower is a relative word, it is still 12 Mbps), but this is a limitation of the serial interface (the fastest speed that a serial device can work at is up to 1 Mbps and even that is rare).

Prolific chipsets are most commonly just used in 1 or 2-port models because they require a separate powered hub in order to add additional ports (this is not the case with Moschip). If you just need a single USB to Serial and you care about compatibility, you will be happy with the Prolific chipset.