USB-1, USB-2


USB-1 (v1.0: 1996, v1.1: 1998) supports the following speeds:
Slow speed
1.5Mbit/s, max 1023 bytes per packet
Full speed
12Mbit/s, max 1023 bytes per packet
Every millisecond, the host must send a SOF packet

USB-2 (v2.0: 2000) supports the following speeds:
Slow speed
Full speed
High speed
480Mbit/s, 8kB per packet
The host sends a SOF packet every 125 usecs (8kHz)

Beware: there are USB-2.0 devices that only support full-speed