A modification of standard Token Bus to implement a prioritized access scheme was proposed to allow transmission of short and periodic messages with a low delay compared to the one for long messages.
12.
Also as a B . Sc . student, he was involved in the design of the first Portuguese personal computer, ENER 1000, in the early 1980s, and later, during his M . Sc ., developed the network interface card for this computer, which implemented a token bus medium access control protocol entirely developed by him.
13.
However, since IEEE 802.3 ( Ethernet ) and IEEE 802.4 ( Token Bus ) send the bytes ( octets ) over the wire, left-to-right, with least significant bit in each byte first, while IEEE 802.5 ( Token Ring ) and IEEE 802.6 send the bytes over the wire with the most significant bit first, confusion may arise when an address in the latter scenario is represented with bits reversed from the canonical representation.
