Three questions about "arduino and LCD"

Using Arduino Displays
1

I dont know why the creator of library for use LCD used pins 2,3,4,5 for data and he used 11 12 for control when he can used 6 and 7. Are someone explication, or is only his chose or there are some reason more important?
Excuse me for my bad english
There are other question that I did in spanish fórum and anybody give me a solution.
I have two LCD that dont work when others work good with same configuration and program
Displays that dont work are new and is

Crystal clear technology
C220x2 20 caracters y 2 línes

http://www.cct.com.my/product001.htm

I have two complitly news . If I conect to 5 V and put my finger in data and control pins there are noise in the LCD, I think that it is OK, but dont work with arduino and with Hello World program, With others displays diferent work good with same program and arduino, only changing LCD .
Where can be the problema?

Third question is about one graphics LCD
I have 5 of this, it is

EPSON EG2401
http://www.dougrice.plus.com/hp/LCDdata/index.htm

Where can I found library for this displays?

Thank you very much for all and excuse me again for my english, I tried post in spanish fórum but there arent solution.

2

I dont know why the creator of library for use LCD used pins 2,3,4,5 for data and he used 11 12 for control when he can used 6 and 7. Are someone explication, or is only his chose or there are some reason more important?

There is no particular reason for the choice of those particular pins. In the examples they do not really make it very clear that you can use any available I/O pin for any of the LCD lines. It is spelled out if you dig deeply enough --> LiquidCrystal - Arduino Reference <-- , but a simple comment would probably be sufficient.

//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);      // put your pin numbers here

Don

3

Your graphics display seems to be a controllerless display. Controlling such a device is very hard and might be impossible. To my knowledge, there is no library available. Look out for a graphics display with well known controller (KS0108, ST7920 or ST7565).

Oliver

4

Thank you very much.