Grass Valley 2200 - Manual (Page 48)

3-24
Section 3 Ð Editor Interface Commands
For PGM-PST/DSK the format of the Write Transition Mode byte is as follows:
After BKGD is set to ON, the next transition will occur on the PGM-PST bus.
NOTE: Do not issue this command more than once per video field. If you do, the
last command sent will be the one executed.
Bit Bit
7 6 5 4 3 2 1 0
0 0 0 X X X X X
1 = DSK 2 on
1 = DSK 1 on
1 = BKGD on (or PGM on for 4000-2A)
1 = PST on for 4000-2A in layered mode
1 = Key Priority On