1.17 Perform subtraction on the given unsigned numbers using the 10’s complement of the subtrahend. Where the result should be negative, find its 10’s complement and affix a minus sign. Verify your answers.
(a) 4,637 - 2,579
(b) 125 - 1,800
(c) 2,043 - 4,361
(d) 1,631 - 745
1.19 The following decimal numbers are shown in sign-magnitude form: +9,286 and +801. Convert them to signed-10’s-complement form and perform the following operations (note that the sum is +10,627 and requires five digits and a sign).
(a) (+9,286) + (+801)
(b) (+9,286) + (-801)
(c) (-9,286) + (+801)
(d) (-9,286) + (-801)
1.21 If the numbers (+9,742) 10 and (+641) 10 are in signed magnitude format, their sum is (+10,383) 10 and requires five digits and a sign. Convert the numbers to signed-10’s-complement form and find the following sums:
(a) (+9,742) + (+641)
(b) (+9,742) + (-641)
(c) (-9,742) + (+641)
(d) (-9,742) + (-641)
1.23 Represent the unsigned decimal numbers 791 and 658 in BCD, and then show the steps necessary to form their sum.
1.25 Represent the decimal number 6,248 in (a) BCD, (b) excess-3 code, (c) 2421 code, and (d) a 6311 code.
1.27 Assign a binary code in some orderly manner to the 52 playing cards. Use the minimum number of bits.
1.29* Decode the following ASCII code: 1010011 1110100 1100101 1110110 1100101 0100000 1001010 1101111 1100010 1110011.