Friday, February 19, 2010

Exercises – Chapter 1

1. Write a sequence of instructions for SIC to ALPHA equal to the product of BETA and GAMMA. Assume that ALPHA, BETA and GAMMA are defined as in Fig.1.3(a).

Assembly Code:

LDA BETA
MUL GAMMA
STA ALPHA
:
:
ALPHA RESW 1
BETA RESW 1
GAMMA RESW 1

2. Write a sequence of instructions for SIC/XE to set ALPHA equal to 4 * BETA – 9. Assume that ALPHA and BETA are defined as in Fig. 1.3(b). Use immediate addressing for the constants.

Assembly Code:

LDA BETA
LDS #4
MULR S,A
SUB #9
STA ALPHA
:
:
ALPHA RESW 1

3. Write SIC instructions to swap the values of ALPHA and BETA.

Assembly Code:

LDA ALPHA
STA GAMMA
LDA BETA
STA ALPHA
LDA GAMMA
STA BETA
:
:
ALPHA RESW 1
BETA RESW 1
GAMMA RESW 1

4. Write a sequence of instructions for SIC to set ALPHA equal to the integer portion of BETA ÷ GAMMA. Assume that ALPHA and BETA are defined as in Fig.1.3(a).

Assembly Code:

LDA BETA
DIV GAMMA
STA ALPHA
:
:
ALPHA RESW 1
BETA RESW 1
GAMMA RESW 1

5. Write a sequence of instructions for SIC/XE to divide BETA by GAMMA, setting ALPHA to the integer portion of the quotient and DELTA to the remainder. Use register-to-register instructions to make the calculation as efficient as possible.

Assembly Code:

LDA BETA
LDS GAMMA
DIVR S, A
STA ALPHA
MULR S, A
LDS BETA
SUBR A, S
STS DELTA
:
:
ALPHA RESW 1
BETA RESW 1
GAMMA RESW 1
DELTA RESW 1

6. Write a sequence of instructions for SIC/XE to divide BETA by GAMMA, setting ALPHA to the value of the quotient, rounded to the nearest integer. Use register-to-register instructions to make the calculation as efficient as possible.

Assembly Code:

LDF BETA
DIVF GAMMA
FIX
STA ALPHA

:
:
ALPHA RESW 1
BETA RESW 1
GAMMA RESW 1

7. Write a sequence of instructions for SIC/XE to clear a 20-byte string to all blanks.

Assembly Code:

LDX ZERO
LOOP LDCH BLANK
STCH STR1,X
TIX TWENTY
JLT LOOP
:
:
STR1 RESW 20
BLANK BYTE C ‘ ‘
ZERO WORD 0
TWENTY WORD 20

8. Write a sequence of instructions for SIC/XE to clear a 20-byte string to all blanks. Use immediate addressing and register-to-register instructions to make the process as efficient as possible.

Assembly Code:

LDT #20
LDX #0
LOOP LDCH #0
STCH STR1,X
TIXR T
JLT LOOP
:
:
STR1 RESW 20

9. Suppose that ALPHA is an array of 100 words, as defined in Fig. 1.5(a). Write a sequence of instructions for SIC to set all 100 elements of the array to 0.

Assembly Code:

LDA ZERO
STA INDEX
LOOP LDX INDEX
LDA ZERO
STA ALPHA, X
LDA INDEX
ADD THREE
STA INDEX
COMP K300
TIX TWENTY
JLT LOOP
:
:
INDEX RESW 1
ALPHA RESW 100
:
ZERO WORD 0
K300 WORD 100
THREE WORD 3

10. Suppose that ALPHA is an array of 100 words, as defined in Fig. 1.5(a). Write a sequence of instructions for SIC/XE to set all 100 elements of the array to 0. Use immediate addressing and register-to-register instructions to make the process as efficient as possible.

Assembly Code:

LDS #3
LDT #300
LDX #0
LOOP LDA #0
STA ALPHA, X
ADDR S, X
COMPR X, T
JLT LOOP
:
:
ALPHA RESW 100

11. Suppose that ALPHA is an array of 100 words. Write a sequence of instruction for SIC/XE to arrange the 100 words in ascending order and store result in an array BETA of 100 elements.

Assembly Code:

NOT YET SOLVED

12. Suppose that ALPHA and BETA are the two arrays of 100 words. Another array of GAMMA elements are obtained by multiplying the corresponding ALPHA element by 4 and adding the corresponding BETA elements.

Assembly Code:

LDS #3
LDT #300
LDX #0
ADDLOOP LDA ALPHA, X
MUL #4
ADD BETA, X
STA GAMMA, X
ADDR S, X
COMPR X, T
JLT ADDLOOP
:
:
ALPHA RESW 100
BETA RESW 100
GAMMA RESW 100

13. Suppose that ALPHA is an array of 100 words. Write a sequence of instructions for SIC/XE to find the maximum element in the array and store results in MAX.

Assembly Code:

LDS #3
LDT #300
LDX #0
CLOOP LDA ALPHA, X
COMP MAX
JLT NOCH
STA MAX
NOCH ADDR S, X
COMPR X, T
JLT CLOOP
:
:
ALPHA RESW 100
MAX WORD -32768

14. Suppose that RECORD contains a 100-byte record, as in Fig. 1.7(a). Write a subroutine for SIC that will write this record on to device 05.

Assembly Code:

JSUB WRREC
:
:
WRREC LDX ZERO
WLOOP TD OUTPUT
JEQ WLOOP
LDCH RECORD, X
WD OUTPUT
TIX LENGTH
JLT WLOOP
RSUB
:
:
ZERO WORD 0
LENGTH WORD 1
OUTPUT BYTE X ‘05’
RECORD RESB 100

15. Suppose that RECORD contains a 100-byte record, as in Fig. 1.7(a). Write a subroutine for SIC that will write this record on to device 05.

Assembly Code:

JSUB WRREC
:
:
WRREC LDX #0
LDT #100
WLOOP TD OUTPUT
JEQ WLOOP
LDCH RECORD, X
WD OUTPUT
TIXR T
JLT WLOOP
RSUB
:
:
OUTPUT BYTE X ‘05’
RECORD RESB 100

16. Write a subroutine for SIC that will read a record into a buffer, as in Fig.1.7(a). The record may be any length from 1 to 100 bytes. The end of record is marked with a “null” character (ASCII code 00). The subroutine should place the length of the record read into a variable named LENGTH.

Assembly Code:

JSUB RDREC
:
:
RDREC LDX ZERO
RLOOP TD INDEV
JEQ RLOOP
RD INDEV
COMP NULL
JEQ EXIT
STCH BUFFER, X
TIX K100
JLT RLOOP
EXIT STX LENGTH
RSUB
:
:
ZERO WORD 0
NULL WORD 0
K100 WORD 1
INDEV BYTE X ‘F1’
LENGTH RESW 1
BUFFER RESB 100

17. Write a subroutine for SIC/XE that will read a record into a buffer, as in Fig.1.7(a). The record may be any length from 1 to 100 bytes. The end of record is marked with a “null” character (ASCII code 00). The subroutine should place the length of the record read into a variable named LENGTH. Use immediate addressing and register-to-register instructions to make the process as efficient as possible.

Assembly Code:

JSUB RDREC
:
:
RDREC LDX #0
LDT #100
LDS #0
RLOOP TD INDEV
JEQ RLOOP
RD INDEV
COMPR A, S
JEQ EXIT
STCH BUFFER, X
TIXR T
JLT RLOOP
EXIR STX LENGTH
RSUB
:
:
INDEV BYTE X ‘F1’
LENGTH RESW 1
BUFFER RESB 100

20 comments:

  1. plz solve 11th question...thank u

    ReplyDelete
  2. sir 2nd qn ..
    BETA RESW 1 is also there na?

    ReplyDelete
  3. Great blog! Really helped me understand the language and how to code in it. Please post the solution to #11 as soon as you solve it. :) Thank you!!!

    ReplyDelete
  4. it still works better and more efficiently than almost every other location-based social networking service.
    sic code
    Standard Industrial Classification

    ReplyDelete
  5. Thanks Sir.!

    It Helped Me a lot ..!!

    ReplyDelete
  6. thank u its very useful!!!!!!!!!!!!!1111

    ReplyDelete
  7. The Solution for Question 11

    Program to sort ARRAY into ascending order.

    SORT START 0
    OUTER LDX INDEX
    LDS ARR1,X
    LDX #0
    INNER LDT ARR1,X
    COMPR S,T
    JLT LOOP
    JEQ LOOP
    RMO S,A
    RMO T,S
    RMO A,T
    RMO X,A
    LDX INDEX
    STS ARR1,X
    RMO A,X
    STT ARR1,X
    LOOP RMO X,A
    ADD #3
    COMP LENGTH
    RMO A,X
    JLT INNER
    LDA INDEX
    ADD #3
    COMP LENGTH
    STA INDEX
    JLT OUTER

    ARR1 RESW 10
    LENGTH WORD 30
    INDEX WORD 0
    END

    ReplyDelete
  8. Oh Nice you punnu my rockstar!! Life savior !! :D NAAIICE !!

    ReplyDelete
  9. please complete question number 1 and 10
    and answer for this question, write a sequence of instructions for SIC to transfer 100 bytes of data from input to output device input and output device number's 07 and 05

    ReplyDelete
  10. Could you help me with this question (generation of multiplication table using subroutine in Sic ) please i couldn't figure it out .

    ReplyDelete
  11. QN. 3 ALTERNATE SOLUTION
    LDX ALPHA
    LDA BETA
    STA ALPHA
    STX BETA

    ALPHA RESW 1
    BETA RESW 1

    ReplyDelete