VIDC20 Data Sheet
4.1.17 Vertical Border Start Register (VBSR): Address 92H
This 13 bit register defines the time, in units of a raster, from the start of the VSYNC puke to the start of the border display.
If N rasters are required in this time, then value (N-1) should be programmed into the VBSR.
If no border is required, this register must still be programmed, in this case to the same value as the VDSR. 31 30 29 26 27 26 25 26 23 22 21 20 19 16 17 16 16 14 13 12 71 10 9 8 7 6 5 4 3 2 1 0 1 0 0 1 0 0 1 0	% X % % % % X X X X %X XI
VBSR value
4.1.18 Vertical Display Start Register (VDSR): Address 93H
This 13 bit register defines the time, in units of a raster, from the start of the VSYNC pulse to the start of the video display.
If N rasters are required in this time, then value (IY-1) should be programmed into the VDSR.
31 30 29 26 27 26 25 24 23 22 21 20 19 16 17 16 15 14 13 12 11 10 9 6 7 6 5 4 3 2 1 0 1 0 0 7 0 0 1 1	% % X X X X X % X X X % X
vosR Xdae
4.1.19 Vertical Display End Register (VDER): Address 94H
This 13 bit register defines the time, in units of a raster, from the start of the VSYNC pulse to the end of the video display. (i.e. the first raster on which the display is not present).
If N rasters are required in this time, then value (N-1) should be programmed into the VDER. 31 30 29 26 27 26 26 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10	9	8	7	6	5	4	3	2	1	0
1 0 0 1 0 1 0 0	X % % X X X X X % X% % %I
VDERV&us