Specifications

106
The checker pattern is reversed.
C/BS (BS) key ⇑ ⇓ ENT key
The gray screen appears with a one-dot wide white outline.
C/BS (BS) key ⇑ ⇓ ENT key
Forty eight right-angled triangles appear.
C/BS (BS) key ⇑ ⇓ ENT key