migration from 16F876a to 18F25k22

[MOUNTAIN747]

Thanks Robert for your comments. Yep, I've looked at evey piece of document I can find and the microelektronika schematic is the only thing I can find to give me any idea of what to do with Vo, and of course they are not using the same GLCD so its just a roll of the dice and hope for the best.

The attatched datasheet shows the Negative Voltage Generator at the bottom right of the page. notice V0 is an input to the NVG. So, Robert, do you think V0 is a Ground reference for the NVG. If we look at the easypic_v7 data sheet, microelektronika takes Vo to a 10k pot to the NVG, which of course will bring Vo bellow Vss. I think I will start with the 10k pot to ground and if the contrast is not great enough I tie the pot to NVG. I will use your advise on how to handle the LED's. Are you using only a 15 ohm resistor on LEDA?

CN2 GLCD uses 20 pin FFC cable
Pin function description My Action
1. VSS GND GND
2. VDD Logic Power input +5V
3. VO LCD contrast control POT 4kohm
4. AO Command / Data Select U1.RA.7
5. /WR 8080: Data Write U1.RC.0
6. /RD 8080: Data Read U1.RC.1
7. DO Data buss line0 U1.RD.0
8. D1 Data buss line1 U1.RD.1
9. D2 Data buss line2 U1.RD.2
10. D3 Data buss ilne3 U1.RD.3
11. D4 Data buss line4 U1.RD.4
12. D5 Data buss line5 U1.RD.5
13. D6 Data buss line6 U1.RD.6
14. D7 Data buss line7 U1.RD.7
15. /CS LCD Controller function Reset U1.RC.3
17. VEE Negative voltage output (-23V) ???
18. SEL1 SEL1=L, 8080 interface; GND
19. FGND Front Panel Ground GND
20. NC

CN3 LED wiring
21. LEDA Power for led Backlight(A) POT_500 ohm to Vcc
22. LEDK Power for led Backlight(K) GND

Thanks Again Robert!
Wayne