+psys: cmp word [ppos + 2], 0
+ ja .skipspawn
+
+ call rnd
+ add ax, 128
+ mov [ppos + 2], ax
+ call rnd
+ add ax, 32
+ mov [ppos], ax
+.skipspawn:
+ dec word [ppos + 2]
+ mov ax, [ppos + 2]
+ shr ax, 2
+ imul bx, ax, 320
+ add bx, [ppos]
+ mov byte [es:bx], 0eh
+
+rnd: in al, 40h
+ mov ah, al
+ in al, 40h
+ shr ax, 8
+ ret