<P> M - Systems , an Israeli company later acquired by SanDisk , filed the first patent for a USB flash drive in April 1999 , known as a DiskOnKey . Later in 1999 , IBM filed an invention disclosure by one of its employees . Flash drives were sold initially by Trek 2000 International , a company in Singapore , which began selling in early 2000 . IBM became the first to sell USB flash drives in the United States in 2000 . The initial storage capacity of a flash drive was 8 MB . Another version of the flash drive , described as a pen drive , was also developed . Pua Khein - Seng from Malaysia has been credited with this invention . Patent disputes have arisen over the years , with competing companies including Singaporean company Trek Technology and Chinese company Netac Technology , attempting to enforce their patents . Trek won a suit in Singapore , but has lost battles in other countries . Netac Technology has brought lawsuits against PNY Technologies , Lenovo , aigo , Sony , and Taiwan 's Acer and Tai Guen Enterprise Co . </P>
<P> M - Systems , an Israeli company later acquired by SanDisk , filed the first patent for a USB flash drive in April 1999 , known as a DiskOnKey . Later in 1999 , IBM filed an invention disclosure by one of its employees . Flash drives were sold initially by Trek 2000 International , a company in Singapore , which began selling in early 2000 . IBM became the first to sell USB flash drives in the United States in 2000 . The initial storage capacity of a flash drive was 8 MB . Another version of the flash drive , described as a pen drive , was also developed . Pua Khein - Seng from Malaysia has been credited with this invention . Patent disputes have arisen over the years , with competing companies including Singaporean company Trek Technology and Chinese company Netac Technology , attempting to enforce their patents . Trek won a suit in Singapore , but has lost battles in other countries . Netac Technology has brought lawsuits against PNY Technologies , Lenovo , aigo , Sony , and Taiwan 's Acer and Tai Guen Enterprise Co . </P>
when did the first usb flash drive appear on the retail market
when did the first usb flash drive appear on the retail market
early 2000
early 2000