Quantum Data 802BT User Manual page 560

TOBL
Class
Description
Command syntax
550 Appendix A Command Reference
set levels relative TO BLanking
Custom image primitive
Temporarily changes how the signal levels are determined for a given color intensity level.
The default method uses black as the 0% reference level and peak video as the 100%
level. Inserting TOBL moves the 0% reference point to the blanking (blacker than black)
pedestal level. The reference point remains shifted only for as long as the image is
displayed.
TOBL