"Don't tell me how hard you work. Tell me how you get done."
- James J. Ling

Home » Post Item » Invert String

Invert String

July 30, 2006

; convert small letters to capital AND vice-versa

mov ah,0ah
lea dx,parameter
int 21h

mov ah,02
mov dl,0ah
int 21h
mov dl,0dh
int 21h

; initialize
lea si, input
xor cx, cx
mov cl, [actlen]

; We wish to check if character is a letter
; if yes, capitalize small letters and vice-versa
; if no, copy character

invert:
     mov al, [si]
 
     cmp al, 122
     ja skip

     cmp al, 96
     ja capital

     cmp al, 90
     ja skip

     cmp al, 63
     jb skip

     add al, 32
 
     jmp store

capital:
     sub al, 32

store:
     mov [si], al

skip:
     inc si

loop invert

mov ah, 09
lea dx, input
int 21h

int 20h

parameter label byte
maxlen db 0FF
actlen db ?
input db 0FF dup(’$')

 

Posted by phengpheng at 4:51 pm | permalink

Previous Comments

Acordingly you can

replace 0FF with -1

so, maxlen db -1

Posted by phengpheng at August 4, 2006, 8:50 pm

All comments are moderated. Your comments will not appear here unless approved by the blog owner. Thank you.

Add a comment








     

July 2006
M T W T F S S
« May   Aug »
 12
3456789
10111213141516
17181920212223
24252627282930
31  

About Me

A Computer Science graduate who is a fanatic in assembly, java, and j2me programming. Developed BlueVoice system (Direct Voice Communication in Mobile Phones), this system allows mobile users to experience FREE VOICE CALLS

Subscribe

Technorati
Bloglines

Tagboard

Jun Mark:

hoW tO creaTE a PrOGram thAT woULD oUTpuT ascii table???

Jun Mark:

pLZ anSwer mY qUEstions

cutieGurl:

how to convert binary to hexadecimal, decimal and octal?????????please. answer me??????????

mary ann:

kuya, ung binary to decimal converter nyo. mali man? ung sa mga compare mo. ung may 0,9,A,F etc… bad character lumalabaspls rep asap po. tnx

carol:

how to convert decimal to binary to octal and hexadecimal

Galwin:

been here!

galwin:

nice site. hope you could visit mine, too.

pathy:

FRIENDS FOREVER!! Miss you na!!!

ridvan:

aus, i seldom see lady programmers. hehe. keep it up. and oh yeah, i guess i saw you during the MICT Quiz Show held in cdo. :)
keep up the codes!

phengpheng:

I miss updating this blog… Sana may time and pc ako to learn new stuffs aside from my work…

support:

Congratulations, you’ve just completed the installation of this shoutbox.

pheng:

uy! you’re here again!

Jay:

Woooohhhh orange…sweat… nakakasilaw! hehe :)

jay:

tagboard flood hehe sensya… had nothing fun to do. :)

pheng:

jaaaaayyyyy….:) ketal man?:)

niel:

no spamming please :p hehehe joke lang jay.

Jay:

Uyyyyyy!!!! Grraaaaaaaiiiinnnneeee
:)
Sssshhhh, el sikret! :)
Niiiiiiiiiiiiieeeeeel
Sup dude!!!!
Paaaaaaaaaaaaaathy
Ketal!?

niel:

ei pheng! :D slick-elegant layout! love it!

yue:

phengpheng!

pheng:

ur welcome!:)

Leave a message ▼