MAC283 CLASSWORK NO 11 a. (Classwork is due before your next class.)
1. Write a line by line explanation to this program. 2. What does the program do at every routine?Explain.
explain step by step using Microsoft words here is the code
.model small XXXXXXXXXXstack 100h .data msg1 db 13, 10, "Enter any number --> ", "$" msg2 db "Enter an operation +,- * or / --> ",13, 10, "$" msg3 db "The Operation is --> ", "$" msg4 db "The result is --> ", "$" By_base dd 21 by_10 dd 10 ; 32 bits variable with initial value = 10 sp_counter db 0 ; 8 bits variable with initial value of zero disp_number dd 0 ; 32 bits variable with initial value = 0 disp_number2 dd 0 disp_number3 dd 0 op_type db 0 last_key dd 0 ; 32 bits variable with initial value of zero remainder db 0 .code main proc mov ax,@data ; set up data segment mov ds,ax XXXXXXXXXXmov dx,offset msg1 call display_message call m_keyin call operation mov dx,offset msg1 call display_message call m_keyin cmp op_type, "+" jnz short skip_plus call op_plus skiP_plus: cmp op_type, "-" jnz short skip_minus call op_minus skip_minus: cmp op_type, "*" jnz short skip_mul call op_mult skip_mul: cmp op_type, "/" jnz short skip_div call op_div skip_div: call m_display mov ax, 4c00h int 21h operation proc mov dx,offset msg2 rpt4: call display_message mov dx,offset msg3 call display_message mov ah, 1 int 21h cmp al, 30h jns rpt4 mov op_type, al ret operation endp m_display proc mov dx,offset msg4 call display_message mov eax, disp_number mov sp_counter, 0 Base_lp: LP1: mov edx, 0 div By_Base push dx inc sp_counter cmp eax, 0 jnz lp1 LP2: pop dx call display dec sp_counter jnz lp2 mov edx, -8 call display mov edx, by_base call display mov edx, -7 call display dec By_base mov eax, disp_number cmp By_base, 1 jnz Base_lp ret m_display endp op_minus proc mov eax, disp_number2 sub eax, disp_number3 mov disp_number, eax ret op_minus endp op_div proc mov eax, disp_number2 div disp_number3 mov disp_number, eax mov remainder, dl call display call m_display mov dl, -16 call display mov dl, remainder call display mov dl, -1 call display mov edx, disp_number3 call display mov ax, 4c00h int 21h op_div endp op_mult proc mov eax, disp_number2 mul disp_number3 mov disp_number, eax ret op_mult endp op_plus proc mov eax, disp_number2 add eax, disp_number3 mov disp_number, eax ret op_plus endp display proc add dl, 30h cmp dl, 3ah js short skip_hex add dl, 7 Skip_hex: mov ah, 6 int 21h ret display endp display_message proc mov ah, 9 ; to display to screen the string pointed by the DX register. int 21h mov edx, 0 ret display_message endp m_keyin proc MOV disp_number, 0 mov last_key, 0 LP_key:; location in the program label mov eax, disp_number mul by_10 ; eax = (eax) * 10 add eax, last_key mov DISP_NUMBER, eax ; save it to the number to display mov ah, 1 ; enables a single key entry int 21h AND eax, 000000ffh cmp al, 13 ; compare the key entered to 13 i.e. ascii of CR jz short finkey ; if CR was pressed then exit the enter key routine sub al, 30h ; remove the ascii from the number entered to get a pure number. MOV LAST_KEY, EAX ; save the last digit entered jmp lp_key ; unconditional jump to the enter key routine in a loop finkey: MOV eax, DISP_NUMBER cmp DISP_NUMBER2,0 jnz short skip MOV DISP_NUMBER2, EAX skip: MOV DISP_NUMBER3, EAX ret m_keyin endp main endp end main