Electronic multiplying circuit using ROM - having decimal coded inputs and binary coded outputs and combined with adding circuit having BCD inputs

摘要

An adding and subtracting circuit is combined with a r.o.m. for use as a multiplying circuit. The r.o.m. provides the numbers for the products 1x1 to 9x9. The numbers can be in binary code. The adding and subtracting circuit can be used for multiplication by using the principle of multiple addition. Division can be carried out by multiple subtraction. The basic circuit can be an adding circuit carrying out multiplication by multiple addition. When, for instance, the third position of the multiplicator has the decimal figure 7 and the second position of the multiplicand has the figure 5 and these are duly multiplied, the addition of the binary coded figure 5 occurs in the fourth decade of the associated adding circuit and the addition of the binary coded 3 in the fifth decade of the associated adding circuit.