Monday, August 15, 2011

SYSTEM-SOFTWARE-TUTORIALS-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

9 comments:

  1. wow this helped me a lot Thank you.

    ReplyDelete
  2. Hey it was a helpful blog..can u pls send some basic programs of SIC and SIC/XE ...as i m a beginner...

    ReplyDelete
    Replies
    1. I have been inactive on blogs. And don't have other materials too.

      Delete
  3. common man.... this blog is copied from other blogs... why do u ppl do such things....

    ReplyDelete
    Replies
    1. This blog is for students. I have put the notes and materials which I collected. If you want use them. Am not claiming anything for them.

      Delete
  4. This comment has been removed by the author.

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