CS273

Quiz 6 Solution

Put your social security number in the right hand corner of each page. Please do not put your name anywhere on this quiz. Failure to follow these instructions will cost you 1 point on the quiz. Note: Be sure to show all your work and no calculators. You will have until the end of class to complete the quiz.

1. (5 points) For each of the following code segments, label each for their code structure:
   While (do-while) loop; Repeat (do-until) loop; If-Then-Else; or
   Sequential (linear):

Code Structure Type

a. loop1 ldaa mem1 Repeat Loop
cba
bhi loop1

b. fred ldaa #$99 Sequential
tba
ldaa #44
stab mem1
staa mem2

c. sam beq charlie While Loop
decb
deca
bra sam
charlie tab

d. sanm ldaa first If .. Then .. Else
lanm ldab second
cba
bge bigger
stab large
bra cont
bigger staa large
cont bra sanm

e. larry inx Repeat Loop
ldab wcnt
larry1 subb one While Loop
bcc larry
dec wcnt1
bra larry1

2. (5 points) For each of the following small programs, indicate True (T) or False (F) if the
   code will assemble and execute correctly in the simulator; if False, briefly
   explain why:
   True/False (why)
1. org $f800
   start fcb $ff F - `start’ is not
   ldab start at an instruction
   stab $1004
   endl bra endl
   org $fffe
   fdb start
   
   
2. n fcb $ff F – fcb as no memory
   org $f800 placememt
   start ldab n
   stab $1004
   endl bra endl
   org $fffe
   fdb start
   
   
3. newv equ $ff T
   org $f800
   n fcb newv
   start ldab n
   stab $1004
   endl bra endl
   org $fffe
   fdb start
   
   
4. start org $f800 F - `start’ is not at an
   n fcb $ff instruction
   ldab n
   stab $1004
   endl bra endl
   org $fffe
   fdb start
   
   
5. org $f800 T
   n fcb $f0
   start ldab n
   stab $1004
   endl bra endl
   org $fffe
   fdb start