Octagon PC-500, User Manual

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13-7
PC-500 user’s manual CRTs and flat panels
LCD bias control examples
1. LCDBIAS UP. Write the following program to move the voltage up one
step:
mov ah,0eeh ; LCDBIAS control
mov a1,00h ; up
mov dx,0ffffh
int 17h
2. LCDBIAS DOWN. Write the following program to move the voltage
down one step:
mov ah,0eeh ; LCDBIAS control
mov a1,01h ; down
mov dx,0ffffh
int 17h
≡
Flat panel considerations
Jumper options are available on the PC-500 to accommodate different
flat panel interfaces. W8 allows direct support of 3V and 5V flat panels.
W9 supports shift clock 180
° out of phase. Refer to the wiring diagrams
specific to your flat panel to determine the correct jumper settings. All
wiring diagrams are found in the .txt files on the 65550 utility disk.
Flat panel interface voltage select: W8
The PC-500 supports flat panel interface at either 5V or 3.3V. W8[1-2]
enables flat panel interface at 5V (default). W8[3-4] enables flat panel
interface at 3.3V.
Table 13-2 Flat panel interface voltage select: W8
Pins Description
[1–2] 5V*
[3–4] 3.3V
* = default, pins jumpered
Inverted shift clock signal voltage level select: W9
The PC-500 provides inverted shift clock signals for flat panels, such as
electro-luminescent (EL) displays, at either 5V or 3.3V levels. W9[1-2]
enables the PC-500 to output an inverted shift clock signal at 3.3V.
W9[3-4] enables the PC-500 to output an inverted shift clock signal at
5V (default).