What is the difference between printing signed and unsigned number in assembly (80x86)? -


i have task take existing assembly program prints signed number (word sized), , need change print unsigned numbers (word sized)... please me understand difference , how should accomplish this.

that program prints signed number:

.model  small .stack   100h .data num  dw  -32768 nums db  6 dup(' '),'$'  .code     mov ax, @data     mov ds, ax      mov ax, num     mov bx, 10      mov si, offset nums+5  next:            cwd     idiv bx     cmp dx, 0     jge cont     neg dx cont:     add dl, 48     mov [si], dl     dec si         cmp ax, 0     jz sof     jmp next sof:         cmp num, 0     jge soff     mov byte ptr[si],   '-' soff:     mov ah, 9     mov dx, si     int 21h     .exit end

thanks!

since word size 16 bits, range of signed numbers -32768 32767, range unsigned numbers goes 0 65535. , while you're declaring num -32768, computer represents in hex 0x8000, if it's performing signed operations -32768, if performing unsigned operations +32768.

if use different negative number, -1, 0xffff in hex. if perform unsigned operation on it, interpreted 65535.

note idiv instruction signed division, whereas div instruction unsigned.


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