In Basic the following code looks crazy!

:ClrHome
:For(A,Ymin,Ymax,deltaY
:Horizontal A
:End
:Repeat getKey
:Disp
:DispGraph
:End

It's still there, and I'd say there's a wave effect, but it is definitely much weaker and harder to notice.
And yeah, For(A,Ymin,Ymax,deltaY:Horizontal A:End is about the fastest and smallest way to blacken the screen.

Yay! Back on topic!
I found out while waiting for the library to open today that the MirageOS ON+[any top row key from Y= to graph] speed-change thing changes the effect.  One would think it was common sense but not many people know about that feature.

[offtopic]
I got the blue screen video now, but by this point the whole supposed BSOD thing should probably be another thread at this point.
[/offtopic] hopefully for real

smallest way to blacken the screen.

Actually, this is the smallest:
Shade(Ymin,Ymax)

You should have made you're program more optimized then!
How about the smallest way that does it one line at a time?

You know that most of the programs I wrote for the 83+ were made several years before TI-BASIC Developper opened, back when you could boast about your TI-BASIC skills if you did not close quotes when ending a line of code, right? Back then, we did not know about all those advanced tricks we got today. All people had was the 900 pages TI-83+ guidebook explaining what each command did, where they closed parhentesises and quotes, and the people who had internet at home (and a computer) just had BASIC Guru Online, which has Text(-1, teaches how to not use Lbl/Goto, but lacks most other tricks.

Don't put the blame on me when you never frequented the TI community yourself in 2001-04.

I think it was more to me since the code you posted was more optimized

Shade(Ymin,Ymax)

I see. Don't worry about it

From experience with Shade, though, it was much slower, so it might explain why he did not use it. Sometimes people go for speed instead of size.