Category : Recently Uploaded Files
Archive   : 80XXX_94.ZIP
Filename : SPIRAL.ASM

 
Output of file : SPIRAL.ASM contained in archive : 80XXX_94.ZIP
;---------------------
; Spiral.asm - Author unknown. Flushes screen display down the drain.

.model tiny
.code
public _Spiral

start:
call _Spiral
mov ax,4C00h
int 21h

_Spiral proc far
push ax bx cx dx es ds si di
push cs
pop ds

mov ax,0B800h
mov es,ax ;Set ES = Screen
mov word ptr ds:[Spiral_Count],0Ch
mov word ptr ds:[Starting_Point],0D0h

Spiral_Loop:
mov ax,ds:[Starting_Point]
mov ds:[Step_Count],ax

One_Step_Loop:
mov word ptr ds:[Horiz_Line_Length],39h
mov word ptr ds:[Vert_Line_Length],1
mov di,798h
mov ax,ds:[Spiral_Count]
mov ds:[Line_Count],ax

Move_Horiz_Line_Left:
mov cx,ds:[Horiz_Line_Length]
dec cx

push ds
push es
pop ds
mov si,di
add si,2
cld
rep movsw
pop ds

mov cx,ds:[Vert_Line_Length]
push ds
push es
pop ds
mov si,di
sub si,0A0h
mov ax,0A2h
cld

Move_Vert_Line_Up:
movsw
sub di,ax
sub si,ax
loop Move_Vert_Line_Up

Move_Horiz_Line_Right:
pop ds
mov cx,ds:[Horiz_Line_Length]
push ds
push es
pop ds
mov si,di
sub si,2
std
rep movsw
pop ds
mov cx,ds:[Vert_Line_Length]
inc cx
push ds
push es
pop ds
mov si,di
add si,0a0h
mov ax,0A2h
std

Move_Vert_Line_Down:
movsw
add di,ax
add si,ax
loop Move_Vert_Line_Down

pop ds

add word ptr ds:[Horiz_Line_Length],2
add word ptr ds:[Vert_Line_Length],2
dec word ptr ds:[Line_Count]
jnz Move_Horiz_Line_Left
dec word ptr ds:[Step_Count]
jz Done_One_Spiral
jmp One_Step_Loop

Done_One_Spiral:
sub word ptr ds:[Starting_Point],8
dec word ptr ds:[Spiral_Count]
jz Done_Spiral
jmp Spiral_Loop

Done_Spiral:
pop di si ds es dx cx bx ax
ret


Starting_Point dw ?
Spiral_Count dw ?
Horiz_Line_Length dw ?
Vert_Line_Length dw ?
Step_Count dw ?
Line_Count dw ?
endp _Spiral

end start


  3 Responses to “Category : Recently Uploaded Files
Archive   : 80XXX_94.ZIP
Filename : SPIRAL.ASM

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/