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1. An arithmetic system operates with 3-digit decimal numbers with sign presented in BCD (12 bits), negative numbers utilize the 10's complement form, one decimal digit (4 bits) is occupied by sign: 0 for "+" and 9 for "-". 1a) Show the most positive and the most negative numbers in both decimal and BCD forms. 1b) Present numbers A=+36 and B= -42 in BCD. 1c) Present the 10's complements of A and B in BCD. 1d) Perform the following operations bit-by-bit, show carries, apply BCD correction (add 6) when necessary (the sum of two decimal digits is greater than 9). 1d1) A+B in BCD. 1d2) A - B = A+(-B) in BCD by addition of A and the 10's complement of B. 1d3) B-A= B + (-A) in BCD by addition of B and the 10's complement of A.

Design a code converter that converts a decimal digit from BCD to excess-3 code, the input variables are organized as (A BC D) respectively with A is the MSB, the output variables are organized as (W XY Z) respectively with W is the MSB, put the invalid decimal numbers as don't care. X= BCD'+B'D+B'C X= BC'D'+B'D+BC X= BC'D'+B'D+B'C X= BC'D'+BD+B'C

Draw the graphs of the Manchester, differential Manchester, NRZ-I and NRZ-L schemes for each of the following data streams: 00110011 10101010

A parity bit is "1" on a system which uses odd parity. The data is "C8". The data is: A. Good B. Corrupted C. Artificial D. Real