+ ; blur the screen upwards
+ mov ax, fs
+ mov ds, ax ; let's use ds for this to avoid long instructions
+ xor bx, bx ; use: pointer
+ xor ax, ax ; use: pixel accum
+ xor dx, dx ; use: second pixel
+.blurloop:
+ mov al, [bx]
+ mov dl, [bx + 320]
+ add ax, dx
+ shr ax, 1
+ mov [bx], al
+ inc bx
+ cmp bx, 64000 - 320
+ jnz .blurloop
+
+