;---------------------------------------------------------------
; 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
;-------------------------------
..start
stringOut:
        mov ah,9
        int 21h
        retf



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