;---------------------------------------------------------------
; Program: Math *NASM Version*
; Summary: Attempt complicated math functions in ASM.
; Function: At the start of the program, you are given a
; choice as to which math function you wish to try.
; Simply follow the instructions and you will
; get your answer.
;
; Owner: Wolfman2000
; Date: Changes
; 10/05/06 First version
;---------------------------------------------------------------
;-------------------------------
CPU 8086 ;8086 instructions only
segment st stack ;define the stack segment with st
resb 256 ;reserve 256 bytes for the stack
extern stringOut
;-------------------------------
segment .data ;Data segment
;-------------------------------
welcome db "Choose your function.",13,10
db "1) Factorial",13,10
db "2) Prime Test",13,10
db "3) Quit",13,10,'$' ;The welcome message. A bit long.
again db "Try again.",13,10,'$'
goodbye db "Goodbye.",13,10,'$' ;The goodbye message.
;-------------------------------
segment .text ;Code segment
;-------------------------------
..start
mov ax,seg welcome ;establish addressability
mov ds,ax ;done
intro:
mov dx,welcome ;Print out welcome
call far stringOut
; I'm unsure of how to force putting in a number, and then
; having the user press ENTER.
mov ah,1
int 21h ;read in the choice
cmp al,3 ;Was it one?
ja leaving ;stub: finish later.
mov dx,again
call far stringOut
leaving: ;To be finished later
mov dx,goodbye
call far stringOut
jmp intro
Quit:
mov ax,4c00h ;quit
int 21h ;yep
----------------------------------------------------------------
CPU 8086
; extern ..start
;-------------------------------
segment .text
;-------------------------------
stringOut:
mov ah,9
int 21h
retf
----------------------------------------------------------------