Introduction

After each module, Digital Challenge gives the option to print out a "Certificate of Competency".  Do not print out the certificate.  Instead, record the score on the lab exercise sheet and have it verified by the lab instructor or assistant.  This will be the scoring record.

Equipment

Notes

• In the counting modules, remember that each time a digit rolls over from the largest symbol to the smallest, the digit in the next position to the left must be changed to the next available symbol. This may cause that digit to roll over as well, in which case the digit in the next position to the left must be changed as well and so on.
• Two of the required modules make use of the octal number system. This is a base 8 number system that uses the digits 0 through 7. Since 8 = 2³, each octal digit corresponds to exactly 3 binary digits, conversion between binary and octal numbers is performed just as it is between binary and hexadecimal numbers except that we deal with only 3 bits at a time.
• The Number conversion module also refers to a number system called BCD or Binary Coded Decimal. This number system is based on coding each decimal digit with its 4 bit binary equivalent, that is:

0	1	2	3	4	5	6	7	8	9
0000	0001	0010	0011	0100	0101	0110	0111	1000	1001

Converting back and forth between binary and BCD is done just as conversion between Hex and Binary is, thus 369₁₀ = 0011 0110 1001_BCD. Note that BCD is not binary. In fact, 369₁₀ = 101110001₂, which takes one less bit than the BCD representation, even when you don't count the leading 0's in the BCD. It should be clear that binary will always be more compact than BCD since BCD never uses the any of the six 4-bit binary numbers 1010₂ through 1111₂.

1. First, log on to the system
Make sure the switch box at your station is set to the "A" position and that the monitor and the computer (the one in the tower case) are both on. You may have to move the mouse, or press the spacebar on the keyboard in order to wake up the computer and cause the screen to come out of sleep mode. If the mouse apears to be inactive, the system may need to be rebooted. If someone else is still logged on to the system, first log off. Then press Ctrl-Alt-Del to bring up the log on screen. Make sure that the logon domain is "Looney". Type in your user name and password which will both be your last name followed immediately by the first letter of your first name, all lowercase. You will be prompted to change your password on your first login.
If you have a problem with any of this, see the instructor. You may save files in a directory that has been assigned to you on the domain server that has been attached to the Z: directory. These files will not be intentionally erased until after the end of the term, but the directory is not backed up, and files could be lost if the system crashes, so it is a good idea to keep a backup of any files you create. Files stored anywhere else except the assigned directory on the domain server may be removed at any time. Make sure you log off before leaving the lab.
2. Run the Digital Challenge Program
Click on the Digital Challenge Icon on the desktop, or if that is not present, click the start button on the taskbar, then select Programs, Digital and Device Challenge, and finally Digital Challenge.
3. Run each of the following modules
The modules may be done in any order. Each time, record your score for the module and have the instructor verify the score. You may repeat modules in order to improve your score.
 
 

Module	Score
Binary Counting (4 sets)
Octal Counting (4 sets)
Hex Counting (4 sets)
Number Conversion (20 problems)

4. You may optionally run the "Base N Counting" module.
5. You do not have to hand in any lab report or exercise sheet for this lab. Just make sure the instructor has recorded your scores for each module.
6. Log off before leaving the lab.