without serial cable conected you can't change anything. (its a ISA card)
Look in SYS:S/TBC.defaults
TBC 1
VIDEO 100.0
BLACK +7.5
CHROMA 100.0
HUE +0.0
HORIZ +0.00
BLUE +0.0
RED +0.0
COARSE +0.00
FINE 90.0
STROBE 0
FIELD 1
INPUT COMPOSITE
FREEZE OFF
FMODE FRAME
MONO OFF
connect the serial cable and look at the line
INPUT COMPOSITE
