Assembler Developer Forum RSS Feed

Help with 8-bit Input to 3 digit BCD Output ASM

Wed, 26 Nov 2008 17:01:05 -0700

I'm trying to write an ASM code that receives eight-bit binary numbers from a dip-switch and displays the data on 3 seven segment LEDs. If the input is 2 zero numbers meaning all dip-switches are off the output should increment through 10-bytes of data starting at A0000H in three digit decimal format. I also need a time delay of 5 seconds between each address in this case. If the dip-switch is not zero, simply the input should be displayed.

So far, I know how to convert hex to decimal and have a lookup table for the seven-segment display. Could anyone point me towards the solution?

Thanks

HEX to Decimal Conversion

Tue, 25 Nov 2008 11:39:03 -0700

Hi all. I've been programming something to count certain things in a string of ASCII characters and it outputs the results on the screen once it's done. But not everyone reads HEX so i need to find out a way to convert HEX to ASCII and i've been wondering if there's an instruction to do so. I've looked into the x86 instruction set and the only thing that i could think that could do this is with AAA and the likes. Any suggestions would be appreciated as i would like to avoid a hole bunch of code for the conversion. Thanks!

~V

Need resellers of calling cards in Mexico

Mon, 24 Nov 2008 14:42:49 -0700

We provide prepaid calling cards that you can use from Mexico as well as many latin countries. We need resellers. Serious interested partners please Email tamimin@hotmail.com

Sincerely,

Nedal Tamimi
KALL MART INC.
734-629-3808

Some "Assembly" Required

Mon, 24 Nov 2008 03:53:28 -0700

I recently purchased a text about programming assembly language for intel based computers. At the end of my current chapter is this problem;

Write a program that accepts two integers from the user. The program should then calculate the least common multiple. (the smallest number that
you can multiply both input values by evenly). Prime factorization is
the recommended method to accomplish this. To test this part of your program, here are some inputs and outputs.

Input: 3,2 LCM = 6
Input: 5,10 LCM = 10
Input: 4,6 LCM = 12

Next, using these same two input values, determine if they are prime and output the results. Note that if prime factorization is used in the previous step, you have already done this.
Finally, if the numbers are less than 10, multiply each 100 then convert these numbers to packed decimal.

This is meant to be a challenge problem, and therefor optional, but I cannot for the life of me figure out two things.

1. How to find the LCM, and
2. packed decimal?

Neither have been even hinted at in my text. If anyone can point me in the right direction I would be eternally grateful.

File Encryption Using XOR

Sun, 23 Nov 2008 17:18:41 -0700

Hi I need help with my program.

I can't get it to work because there is one error.

TITLE File Encryption Using XOR (FileEncyptionUsingXOR.asm)

; Description: A program that encrypts the contents of a plaintext file and stores it in a cyphertext file.
;
; Revision date: November 23, 2008

INCLUDE Irvine16.inc
.data
prompt BYTE "What is the plain text file: ", 0ah ;asks for the plain text file
prompt2 BYTE "What is the name of the encrypted text file: ", 0ah ;asks for the encrypted text file
prompt3 BYTE "What is the encryption code (1 to 255): ", 0ah ;asks for the encryption code
output BYTE "Plaintext: ", 0ah ;outputs the unencryption text
output2 BYTE "Encryption text: ", 0ah ;outputs the encryption text
newline BYTE 0ah ;next line
input BYTE 80 DUP(0) ;stores the plain text file name
input2 BYTE 80 DUP(0) ;stores the encryption file name
input3 BYTE 0 ;stores the encryption key
bytesRead WORD ? ;stores number of bytes in the input
inHandle WORD ? ;stores the file handle input
outHandle WORD ? ;stores the file handle output
BufferSize = 1000 ;determines the max text file size
Buffer BYTE bufferSize DUP(?) ;stores an array of characters

.code
main PROC
mov ax, @data ;used because of variables
mov ds, ax ;places ax into ds

; ask for the file name
mov ah, 40h ;sets the output array
mov cx, LENGTHOF prompt ;copies LENGTHOF to CX
mov dx, OFFSET prompt ;moves the OFFSET of the string to dx
int 21h ;call MS-DOS

; reads the user's input
mov ah, 3Fh ;sets the read array
mov bx, 0 ;mode = read-only
mov cx, 80 ;max character is 80
mov dx, OFFSET input ;saves the input into dx
int 21h ;call MS-DOS

; asks for cypher text file
mov ah, 40h ;sets the output array
mov cx, LENGTHOF prompt2 ;copies LENGTHOF to cx
mov dx, OFFSET prompt2 ;moves OFFSET of the string to dx
int 21h ;call MS-DOS

; reads the user's input
mov ah, 3Fh ;sets the read array
mov bx, 0 ;mode = read-only
mov cx, 80 ;max character is 80
mov dx, OFFSET input2 ;saves the input into dx
int 21h ;call MS-DOS

; asks for the encryption key
mov ah, 40h ;sets the output array
mov cx, LENGTHOF prompt3 ;copies the LENGTHOF to cx
mov dx, OFFSET prompt3 ;moves OFFSET of the string to dx
int 21h ;call MS-DOS

; reads the encryption key
mov al, 0 ;al is starts at 0
call ReadInt ;read signed integers
mov input3, al ;copies the input in al to input3

; output "Plaintext text: "
mov ah, 40h ;sets the output array
mov cx, LENGTHOF output ;copies the LENGTHOF to cx
mov dx, OFFSET output ;moves OFFSET of the string to dx
int 21h ;call MS-DOS

; opens the plain text file
mov ax, 716Ch ;sets to open a file
mov bx, 0 ;mode = read-only
mov cx, 0 ;normal attribute
mov dx, 1 ;action: open mode
mov si, OFFSET input ;Offsets input
int 21h ;call MS-DOS
jc quit ;quit if error, when CF = 1
mov inHandle, ax ;file handle

; reads the plain text file
mov ah, 3Fh ;sets the read array
mov bx, inHandle ;file handle
mov cx, BufferSize ;max bytes to read
mov dx, OFFSET Buffer ;buffer pointer
int 21h ;call MS-DOS
jc quit ;quit if error, when CF = 1
mov bytesRead, ax ;numbers of bytes read

; outputs the plain text from file
mov ah, 40h ;sets the output array
mov bx, 1 ;console output handle
mov cx, bytesRead ;number of bytes
mov dx, OFFSET Buffer ;buffer pointer
int 21h ;call MS-DOS
jc quit ;quit if error, when CF = 1

; converts plain text to cypher
mov ecx, BufferSize ;sets the loop
mov esi, 0 ;starts the pointer at 0

L1:
xor Buffer[esi], input3 ;Translate the bytes (line 104)
inc esi ;go to next byte
loop L1 ;repeat the loop

; open cypher text file
mov ax, 716Ch ;sets to open a file
mov bx, 1 ;mode = write-only
mov cx, 0 ;normal attribute
mov dx, 12h ;action: create/truncate
mov si, OFFSET input2 ;Offsets input2
int 21h ;call MS-DOS
jc quit ;quit if error, when CF = 1
mov outHandle, ax ;save handle

; write to cypher text file
mov ah, 40h ;sets the write array
mov bx, outHandle ;output file handle
mov cx, bytesRead ;number of bytes
mov dx, OFFSET Buffer ;buffer pointer
int 21h ;call MS-DOS
jc quit ;quit if error, when CF = 1

; Output "Encryption text: "
mov ah, 40h ;sets the write array
mov bx, 1 ;console output handle
mov cx, LENGTHOF output2 ;copies LENGTHOF to cx
mov dx, OFFSET output2 ;moves OFFSET of the string to dx
int 21h ;call MS-DOS

; output the cypher text from file
mov ah, 40h ;sets the write array
mov bx, 1 ;console output handle
mov cx, bytesRead ;number of bytes
mov dx, OFFSET Buffer ;buffer pointer
int 21h ;call MS-DOS
jc quit ;quit if error, when CF = 1

; New line
mov ah, 40h ;sets the write array
mov cx, LENGTHOF newline ;copies LENGTHOF to cx
mov dx, OFFSET newline ;moves OFFSET of the string to dx
int 21h ;call MS-DOS
quit:
exit

main ENDP

END main

The error is line 104: error A2070: invalid instruction operand and to help I indicated where that line is.

WILL $$$$ PAY FOR HELP WRITEING THIS PROGRAM !!!!!!!!!!! Z80

Sat, 22 Nov 2008 20:35:31 -0700

20 - 50 DOLLARS FOR HELP MY EMAIL ADDRESS IS : NOCMSA@YAHOO.COM CONTACT ME FOR MORE INFORMATION
1.Write a Z80 program that reads 10 bytes of data from and array
whose base address starts at 2020H, adds each data byte to 2H and then stores
the sum at a 10 byte array whose base address is 3020H. Show solution with
comments for each line & fully explain how it works.

2: Interpret and fully explain the function of the following program.
Provide a full explanation and comments for each line. Hint: 2040H contains
the data byte 22H. What is the resulting number, in hex, which is contained in
the address 2070H after the program when the program halts?
Memory Address Z80 Machine Code
300A 21 #
300B 40 #
300C 20 #
300D 01 #
300E 70 #
300F 20 #
3010 7E #
3011 3C #
3012 A6 #
3013 02 #
3014 36 #
3015 00 #
3016 76 #

3: Write a PIC 18 Series Assembly Program, (i.e. just the Main), to
take in an 8 bit literal number, A, and an 8 bit literal number, B, and to
obtain C = A x B, and to store C in variables, Shigh, and Slow, respectively,
Then have the program multiply each of them, i.e. Shigh and Slow by 4, Mod 256,
without using the multiply function.

4: Interpret and fully explain the following program (next sheet),
which is written in PIC 18 Assembly language. Provide comments and a general
explanation of what the program does.
Solution / Explanation:
;************************************************* *****************************
; This file is a basic template for creating relocatable assembly code for *
; a PIC18F4520. Copy this file into your project directory and modify or *
; add to it as needed. Create a project with MPLINK as the language tool *
; for the hex file. Add this file and the 18F4520.LKR file to the project. *
; *
; The PIC18FXXXX architecture allows two interrupt configurations. This *
; template code is written for priority interrupt levels and the IPEN bit *
; in the RCON register must be set to enable priority levels. If IPEN is *
; left in its default zero state, only the interrupt vector at 0x008 will *
; be used and the WREG_TEMP, BSR_TEMP and STATUS_TEMP variables will not *
; be needed. *
; *
; Refer to the MPASM User's Guide for additional information on the *
; features of the assembler and linker. *
; *
; Refer to the PIC18Fxx20 Data Sheet for additional *
; information on the architecture and instruction set. *
; *
;************************************************* *****************************
; *
; Filename: *
; Date: *
; File Version: *
; *
; Author: *
; Company: *
; *
;************************************************* *****************************
; *
; Files required: P18F4520.INC *
; 18F4520.LKR *
; *
;************************************************* *****************************
LIST P=18F4520, F=INHX32 ;directive to define processor and file format
#include <P18F4520.INC> ;processor specific variable definitions
;************************************************* *****************************
;Configuration bits
;Microchip has changed the format for defining the configuration bits, please
;see the .inc file for futher details on notation. Below are a few examples.
; Oscillator Selection:
CONFIG OSC = LP ;LP
;************************************************* *****************************
;Variable definitions
; These variables are only needed if low priority interrupts are used.
; More variables may be needed to store other special function registers used
; in the interrupt routines.
; Test variables, simple sum
UDATA
WREG_TEMP RES 1 ;variable in RAM for context saving
STATUS_TEMP RES 1 ;variable in RAM for context saving
BSR_TEMP RES 1 ;variable in RAM for context saving
MUL RES 1 ;
SPECIAL RES 1 ;
INTDIV1 RES 1 ;
IntDiv RES 1 ;
UDATA_ACS
EXAMPLE RES 1 ;example of a variable in access RAM
;************************************************* *****************************
;EEPROM data
; Data to be programmed into the Data EEPROM is defined here
DATA_EEPROM CODE 0xf00000
DE "Test Data",0,1,2,3,4,5
;************************************************* *****************************
;Reset vector
; This code will start executing when a reset occurs.
RESET_VECTOR CODE 0x0000
goto Main ;go to start of main code
;************************************************* *****************************
;High priority interrupt vector
; This code will start executing when a high priority interrupt occurs or
; when any interrupt occurs if interrupt priorities are not enabled.
HI_INT_VECTOR CODE 0x0008
bra HighInt ;go to high priority interrupt routine
;************************************************* *****************************
;Low priority interrupt vector
; This code will start executing when a low priority interrupt occurs.
; This code can be removed if low priority interrupts are not used.
LOW_INT_VECTOR CODE 0x0018
bra LowInt ;go to low priority interrupt routine
;************************************************* *****************************
;High priority interrupt routine
; The high priority interrupt code is placed here.
CODE
HighInt:
; *** high priority interrupt code goes here ***
retfie FAST
;************************************************* *****************************
;Low priority interrupt routine
; The low priority interrupt code is placed here.
; This code can be removed if low priority interrupts are not used.
LowInt:
movff STATUS,STATUS_TEMP ;save STATUS register
movff WREG,WREG_TEMP ;save working register
movff BSR,BSR_TEMP ;save BSR register
btfsc PIR1,0 ;
goto int_timer1 ;
btfsc INTCON, 1 ;
goto int_extpin33 ;
goto int_end ;
int_timer1 ;
incf SPECIAL
movf SPECIAL,W
addlw 0x30 ;
movwf TXREG
movlw Timer1L ;
movwf TMR1L ;
movlw Timer1H ;
movwf TMR1H ;
bcf PIR1,0 ;
decfsz INTDIV1 ;
goto int_end
int_extpin33
movwf TXREG
movlw IntDiv
movwf INTDIV1 ;
bcf INTCON, 1
int_end ;
movff _w, w
movff _status, STATUS
movff _bsr, BSR
retfie ; return from int
movff BSR_TEMP,BSR ;restore BSR register
movff WREG_TEMP,WREG ;restore working register
movff STATUS_TEMP,STATUS ;restore STATUS register
retfie
;************************************************* *****************************
;Start of main program
; The main program code is placed here.
Main:
; *** main code goes here ***
bsf INTCON, 6 ;
clrf MUL ;
movlw 0x44 ;
movwf MUL ;
movlw 0x44 ;
mulwf MUL ;
goto $
;************************************************* *****************************
;End of program
END

Opening a file

Sat, 15 Nov 2008 07:32:41 -0700

Hi! I`m having a problem opening a file in 16 bit assembly. Here`s part of program which prompts user to input filename and using it should open the file but instead it just gives error message. I made a mistake somewhere I think..
Thanks in advance for your help! :)

.model small
.stack 100h
.data

  iveskite db 'Type your filename.$'
  klaid db 'Error reading file.$'
  endln db 13, 10, "$" 
  filename db 20,0,20 dup(?),0
  handle dw ?

.code

  main:  
    mov ax, @data
    mov ds, ax
  
    mov ah, 09h  
    mov dx, offset iveskite
    int 21h
    
    mov ah, 09h
    mov dx, offset endln
    int 21h
    
    mov ah, 0ah ;filename input
    mov dx, offset filename
    int 21h
      
    mov ax, 3d00h
    mov dx, offset filename  ;open file
    int 21h   
    jc klaida
    
    mov handle, ax
    jmp quit
    

  klaida:
  
  mov ah, 09h 
  mov dx, offset endln
  int 21h  

  mov ah, 09h  ;output error message
  mov dx, offset klaid
  int 21h

  quit:
  mov ax,04C00h         ;close program
  int 21h 

end main

Writing Hex Dump program

Wed, 12 Nov 2008 09:14:20 -0700

Hey everybody.
I got a problem writing hex dump program.
Maybe someone of you could help me to find appropriate source related to my program?
I would be very grateful if you could help me!

PIC 16f684 timer0 question

Sun, 09 Nov 2008 12:37:55 -0700

Hi,

I am a beginner at PIC programming and am trying to get timer0 to work as an event counter on external pin T0CK1.

The basic program structure is:

init:
movlw b'00110000' ; Make TMR0 a counter (pull-ups on
movwf OPTION_REG ; T0CK1 enable, falling edge, no pre-scaler

main_loop:

movf TMR0, w
movwf PORTC
delay
goto main_loop

I have a switch connected to T0CK1 that pulls the pin low when pressed and LEDS connected to PORTC to see TMR0 value. I would expect to see the LEDS increment with each button press, but instead I have to press 256 times to see TMR0 increment. Is this how timer0 is supposed to behave as an event counter on an external pin? I have tried different pre-scaler values and nothing has any effect. I am obviously missing something, can someone help me out,

regards

Dave

Logic gates

Tue, 04 Nov 2008 11:05:47 -0700

Hello, how can I use logic gates in assembly? for example, apply an AND in a byte that I have defined. For example, if I have the following variable:

variable db ?

This is a 8 bit element, supposing that it have the following content:

11001111

What I want to do is a apply the AND gate to that bit chain, in this way:

11001111//content of my variable
00000001//I want to apply AND with this bit chain

How can I code that in assembly?

Best regards

deleted

Mon, 03 Nov 2008 20:53:41 -0700

deleted....asdfghjggk

MIPS integer implementation of floating point addition

Thu, 30 Oct 2008 23:38:24 -0700

So I'm trying to write a program in MIPS assembly code to help me better understand how floating point addition works. I understand how a floating point number is broken up into a 1 bit sign, 8 bit exponent, and 23 bit fraction. I've written a program that gets two inputs from a user, and adds them WITHOUT using any floating point instructions except mtc1 and mfc1 (for input and output). My code has bugs because when I add 1 + 2 I get 2.74804688. I'm still trying to debug the code but can't seem to grasp the problem. If anyone can help, I would greatly appreciate it.

THIS IS MY CODE (excluding the user input...the first floating point value is in $s0, and the second in $s1)

#Integer implementation of floating-point addition
#Initialize variables
add $s0,$t0,$zero #first integer value
add $s1,$t1,$zero #second integer value
add $s2,$zero,$zero #initialize sum variable to 0
add $t3,$zero,$zero #initialize SUM OF SIGNIFICANDS value to 0

#get EXPONENT from values
sll $s5,$s0,1 #getting the exponent value
srl $s5,$s5,24 #$s5 = first value EXPONENT

sll $s6,$s1,1 #getting the exponent value
srl $s6,$s6,24 #$s6 = second value EXPONENT

#get SIGN from values
srl $s3,$s0,31 #$s3 = first value SIGN
srl $s4,$s1,31 #$s4 = second value SIGN

#get FRACTION from values
sll $s7,$s0,9
srl $s7,$s0,9 #$s7 = first value FRACTION
sll $t8,$s1,9
srl $t8,$s1,9 #$t8 = second value FRACTION

#compare the exponents of the two numbers
compareExp: ######################

beq $s5,$s6, addSig
blt $s5,$s6, shift1 #if first < second, go to shift1
blt $s6,$s5, shift2 #if second < first, go to shift2
j compareExp

shift1: #shift the smaller number to the right
srl $s7,$s7,1 #shift to the right 1
addi $s5,$s5,1
j compareExp

shift2: #shift the smaller number to the right
#srl $s0,$s0,1 #shift to the right 1
#j compareExp
srl $t8,$t8,1 #shift to the right 1
addi $s6,$s6,1
j compareExp

addSig:

add $t3,$s7,$t8 #Add the SIGNIFICANDS

li $v0, 4
la $a0, sum
syscall

li $v0, 1
move $a0, $t3
syscall

j result

result:
li $v0, 4
la $a0, newline
syscall

sll $t4,$s3,31 #SIGN
#FRACTION
sll $t5,$s6,23 #EXPONENT
add $t6,$t4,$t5
add $t6,$t6,$t3

li $v0, 4
la $a0, sum2
syscall

li $v0, 1
move $a0, $t6
syscall

li $v0, 4
la $a0, newline
syscall

li $v0, 4
la $a0, sum2
syscall

li $v0,2
mtc1 $t6,$f12
syscall
jr $31
# END OF PROGRAM

How to burn a code into a microprocessor

Sun, 26 Oct 2008 08:49:39 -0700

I joined college this year and i also joined robotics club thinking that they will teach how to programme in asm .They are using a compiler called bascom for programming atmega16 microprocessor in basic.But i want to programme a robot in asm or c.So what compiler should i use and how do i burn the programme in microprocessor.I heard of programmer .What is it.Is it a cable used to transfer the programme in the microprocessor
After writing a programme in a baascom the demonstrater clicked a option called burn inm the bascom compiler.The PCB board was connected to a microprocessor with a cable which went behind the CPU where the printer goes .Is that cable called a programmer.But if i amake a programme for a line follwer in my dev c++ compiler how do i transfer it to the microprocessor because in Dev c++ we dont have a burn option.

ASCII capturing

Thu, 09 Oct 2008 10:28:15 -0700

I have an ASCII string coming in on COM1 of my computer. I need to isolate 3 numbers out of that string. The string will change but the values i need will always be in the same place within the string. Anybody have any ideas how i can isolate certain values out of an ASCII string and place them into memory somewhere?
Any help would be great.
Thanks

MIPS...checking least significant bit.

Thu, 09 Oct 2008 08:03:17 -0700

I'm working on an assignment and have reached a road block. If I have a 16 bit integer like:

0000 0000 0000 0100

how would I check to see what the value in the LEAST significant bit is? Basically, how would I check to see if the least significant bit is 0 or 1? How would I code it? I am a beginner at MIPS...is there a simple instruction that detects this? Please help.

MIPS assembly code multiplier/divider.

Wed, 08 Oct 2008 08:26:47 -0700

I have to write an unsigned 16-bit software implementation of a multiplier and a divider in MIPS assembly code. Two positive integers are read from the console. The program is supposed to multiply and divide the two integers, outputting the product, quotient and remainder.

Here is an example run:
Enter an integer: 10
Enter an integer: 4
Product is 40
Quotient is 2
Remainder is 2

I can't use any MIPS multiply/divide instructions either.
CAN SOMEONE PLEASE HELP ME WITH THIS? I'M STILL A BEGINNER WITH MIPS ASSEMBLY LANGUAGE AND WOULD APPRECIATE ANY HELP. I know the process involves shifts, but I really need help with this project...please help.

help in 68k assmbly language

Mon, 06 Oct 2008 15:03:45 -0700

Hello everyone,

i am taking a class about assembly language where we have to use easy68k assembler to write assembly programs,

the teacher sucks and expect us to do everything without explaining anything.

if it is possible i am seeking someones help in my first program.

which is :

write a program that will allow a user to enter an arbitrary number of unsigned integers. Zero is to be used as a sentinel value for the end of input (when the user enters zero, it means they are done entering input). Your program will compute the sum of these numbers. All operations are to be done using 16 bits. An error message will be printed to the screen if an overflow occurs, otherwise the sum will be printed.
Exercises:

* Begin your data area at location $3100.
o Reserve space for 15 words, label it INPUT.
o Define a string that you will use to prompt the user for input, such as

"Enter values, zero when done:"

o Define a string that you will use if the user has entered 15 numbers, such as

"That is all the input allowed. Calculating sum..."

o Define a string that you will use if you need to print an error message, such as

"The values you entered caused an overflow condition."

o Define a string that you will use to ask the user if they want to repeat, such as

"Do you want to repeat? [0=No, 1=Yes]."

* Begin your main routine at location $4000:
o Prompt the user to enter input.
o Loop, reading input using TRAP #15, until the user enters zero.
o As each value is entered, store it sequentially in memory beginning at the location labeled INPUT.
o You only have space for 15 numbers, so if the user enters 15 values print the message above and proceed with the next step.
o Load D0 with the count (the number of values input).
o Load A0 with the address given by INPUT.
o Call the subroutine, SUM, to compute the sum.
o On return, if D0 contains 0, print the sum contained in D1.
o Else if D0 contains 1, print the error message.
o Ask the user if they would like to compute another sum, if so repeat the steps listed above.
o If not, then return control to the simulator using TRAP #15.

* Begin your subroutine at location $4500, label it SUM:
o Expects the count in D0 and the starting address of the input in A0.
o Loop count times, adding each input value to a sum in D1.
o Use indirect addressing to obtain the input values.
o Test for overflow (unsigned).
o Return the value 1 in D0 if an overflow condition occurred.
o Otherwise, return a 0 in D0, and the sum in D1.

* Be sure to document your program.

thanks for anyone's help.........

REVERSING A STRING...

Sun, 05 Oct 2008 12:28:15 -0700

I'm new in assembly language. I have to come up with a complete TASM code for this problem:

Code a program for the following requirements. Define NAME1 with the string "SalesClerk" and NAME2 with 15 blanks. Use LODSB to access each character in NAME1 from left to right. Then use STOSB to store each accessed character into NAME2 from right to left so that NAME2 contains the string in reverse sequence. You have to clear and set the Direction Flag for this procedure. Assemble and Test.

Please Help me... Thank You. This is urgent.

this is the code that I tried, but it doesn't reverse a string.

.model small
.code
org 100h

start:

first proc near

lea si, a1
mov cx, 15
mov ah, 0Eh

a:

LODSB
int 10h
loop a

ret

a1 db,'SalesClerk$'

first endp

second proc near

lea di, a2
mov al, 12h
mov cx, 15

rep STOSB

ret

a2 db, 15 dup(0)

second endp

end start

Numbers in registers assembly

Sun, 05 Oct 2008 08:41:29 -0700

Hello, I have a problem, if I do the following, it works fine for what I need to do:

mov bx,0
mov vector[bx],1

But if I want to put a variable instead the number 1, like this:

mov bx,0
mov ah, offset variable
mov vector[bx],ah

It doesn't works as I want. Someone know how to resolve this?

Best regards

Delay or system pause

Mon, 29 Sep 2008 13:58:06 -0700

Hello, there is some way to do a system pause in assembly? or make a delay?

It could be with interruptions?

Best regards,

Writing in different pages of video memory

Sat, 27 Sep 2008 18:58:15 -0700

Hello, I want to write some numbers in a video memory page, and some other numbers in another video memory page. How can I do that? can someone put a little example? I have been researching on how to do this, but I dont understand the provided examples.

Best regards.

Incrementing CX with a variable

Thu, 25 Sep 2008 13:48:08 -0700

Hello.

I have a counter variable, I declared it as follow:

counter db 1

I initialized that variable in cero:

mov counter,0

What I need is to increment that counter, I have this code:

call incrementCounter
mov cx, counter
mov bx,0
paint:
inc bx
loop pintar
mov colors[bx], 11110000b

The method incrementCounter increment the counter variable, it perform an "inc counter" instruction.

After calling the method, the BX register value have not increased, and I need to increase this value. Somebody know how?

Best regards.

8051 CHIP

Wed, 24 Sep 2008 05:59:34 -0700

hELLO EVERYONE. I AM NEW TO THIS AS I HAVE A MAJOR ISSUE. I AM USING SOFTWARE CALLED PINNACLE TO PROGRAM AN 8051 CHIP TO COUNT UPWARDS. I HAVE 3 7 SEG DISPLAYS SO I NEED ASSISTANCE TO HELP COUNT UP TO 99.9 SECONDS. NEW TO CODE SO ANY HELP APPRECIATED.

DERMOT

Developing a cd-rom driver in assembly

Sun, 21 Sep 2008 05:46:00 -0700

Hello to everybody.
I am trying to build a cd-rom driver (like the mscdex)in assembly. I would like to know how a cpu addresses a cd-rom (specifically amd athlon 64 X2) and where i can fin d more information about this matter. Does anyone know?

I found a driver at sourceforge.net named ODD_DOS_DRIVER but i cannot produse an .exe file from the given source code.I use the nasm assembler.
I have looked in http://www.nasm.us but it says the code should have some specific lines in addition (e.g. ..start:). Can anyone help me to produce the .exe file?

(i have installed MSDOS 6.0 in a VMWare virtual machine.)

Thank you.

Need your help about LISP

Fri, 19 Sep 2008 19:58:01 -0700

Oh God. I need to Learn much in LISP. I really had a hard time reading online tutorials and it doesnt really help. I have no idea at all on how the syntax and codes works. God! I have to master it in a very short period of time.

Can anyone help me?
Just only the basic in executing the project.
I use Allegro Common LISP Software.