Computer Science Assignments 6 & 8

Please disregard question 1, in assignment 6; thank you.

Assignment #6

1. Discuss some situations where a sequential storage device such as tape could be a useful form of mass storage and why?

2. Assuming a square two-dimensional memory organization, what are the dimensions of a memory containing 1 MB (2^20) bytes of storage?

How large would the MAR be?

How many bits are sent to the row and column decoders?

How many output lines would these decoders have?

3. Consider the following structure of the Instruction Register:

OPCODE Address 1 Address 2

6 bits 18 bits 18 bits

a. What is the maximum number of distinct operation codes that can be recognized and executed by the processor on this machine?

b. What is the maximum memory size on this machine?

c. How many bytes are required to store each complete instruction?

Assignment #8

1. Using the Employees table of Figure 14.6, what is the result of the following SQL query?

SELECT *

FROM Employees

WHERE HoursWorked < 100;

2. Write an SQL query that retrieves first and last names and pay rate, ordered by PayRate, from the Employees table of Figure 14.6.

3. Using the Employees table of Figure 14.6 and the Insur-ancePolicies table of Figure 14.7, what is the result of the following SQL query? (The # marks allow the date to be treated numerically.)

SELECT ID, PlanType

FROM Employees, InsurancePolicies

WHERE Birthdate > #1/01/1960# AND ID = EmployeelD;

Table 14.6

ID LastName FirstName BirthDate PayRate HoursWorked

Kay

116		Kay	Janet	3/29/1956	$16.60	94
123	Perreira	Francine	8/15/1987	38.50	185
			149	Takasano	Frederick	5/23/1966	$12.35	250
		171	John	11/17/1954	$17.80	245
165	Honou	Morris	6/9/1988	$6.70	53

Table 14.7

EmployeeID PlanType DateIssued

171

171

149

B2

149

149

	B2	10/18/1974
C1	6/21/1982
8/16/1990
A1	5/23/1995
C2	12/18/1999