ANCIENT COUNTING BOARDS

The Salamis Tablet

Counting boards are the earliest known form of a counting device (excluding fingers and other very simple methods). They were made from natural material such as stone or wood, and the actual counting was done on the board with beads, pebbles, or even colored sand. Not many of these boards survive today because of the perishable materials used in their construction. The oldest known example of a counting board was discovered on the Greek Island of island of Salamis in 1899².

It is thought to have been used by the Babylonians in about 300 B.C. and is more of a gaming board rather than a calculating device. The gaming boards used by ancient cultures such as the Babylonians and the Romans are thought to be the precursors of the Abacus. The Salamis tablet is approximately 150 x 75 x 4.5 cm and is made of marble. Parallel grooves and Greek symbols are carved into it¹. Roman Hand Abacus The Romans are not known for their contributions to the field of mathematics. It is often said that their only notable offering was the murder of Archimedes at the hands of a Roman soldier! However, the Romans did develop the hand abacus and some of the basic technology in the design led indirectly to the success of modern day computers. The Roman abacus contained several long and short grooves, and had up to five beads in each notch. The longer grooves were marked with 1-units, X-tens, and so on (in Roman numerals of course). The shorter grooves denote fives⁴. As this type of addition is essential is a bi-quinary coded decimal system^note1 ,it could be said that the Roman's development of the Abacus paved the way for the construction of the modern computer.

note 1:

Bi-quinary coded decimal was used in some early computers, including the UNIVAC. The term Bi-quinary means two (bi) and five (quinary) code. An example is 10-10000 that represents the number zero on the IBM 650. reference: http://www.book-spot.co.uk/index.php/Bi-quinary_coded_decimal

The Salamis Tablet (1)

Discovered c.1899 and dated to about 300 B.C.

It is the earliest counting board known to exist.


    Roman Hand Abacus (3)
The abacus was one of the earliest calculating devices, a 'step-up' from the more primitive counting board.
The abacus was the first device to provide five fixed decimal orders³and is still used in parts of the Far East.