LCD compatibility

[2PAC Mafia]

Hi guys,

we have a customized LCD 128 x 64 which uses T6963C driver. We bought 2 different LCD´s to make tests of compatibility and after preparing connectors, backlight and bright the units display the graphic correct but the text is moved one line down so sometimes it is over the graphic.
The drivers on the new units are RA6963 and UCI6963, both units have the same wrong behavieur comparing to the original one.
We have compared the pinout H and L fixed pins and we discovered a pin 7 (MD3) which was different but after setting it in same way it has same problem.
We replaced original driver UCI6963 by T6963C and it didn´t work properly, it was worst showing text like double.
We replaced original crystal oscillator used in new boards of 6MHz and put 4MHz used in original customized board, but same problem.
We replaced original RAM, different size on original and new board but this didn´t work, nothing displayed correct at LCD.

I attach some datasheet. Any idea will be welcome. Thank you.

 

[gophert]

It sounds more like a software issue than hardware. Look at the library you're using and see if you can bump the text up one pixel. It may be an issue of counting from 1 vs counting from 0.

 

[picbits]

All the issues I've had with cross compatibility with text based LCD drivers have been down to timing. Have you tried increasing time between issuing instructions ?

Just a thought - could be going totally down the wrong path.

 

[2PAC Mafia]

Thank you guys, we are agree about we also think it is a software issue, but as this is a repair for replacing original LCD using original software we were trying to check all hardware possibilities. I think we have no possibility to go into software to modify instructions at flash...

 

[Pommie]

Some of the earlier bitmapped LCDs required dummy read/write prior to actual data. Could the older display have one of these driver chips? The KS0107 springs to mind.

Mike.
Edit, forget this, I misread your post.