Connections for a standard HD44780 based LCD display.

The HD44780 has an industry standard parallel interface used in many clone
designs.  It can be run in 4-bit or 8-bit mode and requires 8 or 12 control
lines for full functionality (or slightly less if some things are skipped -
like read access)

1	GND
2	+5V
3	Contrast	often GND is fine, but a 10k pot would be better
4	RS	Register select (high=data, low=control)
5	R/W	(low=write)
6	E	Data pins are latched on falling edge of this signal
7	D0
8	D1
9	D2
10	D3
11	D4	Use D4 through D7 for a 4-bit interface and strobe E once for
12	D5	each nibble
13	D6
14	D7

15	Backlight	Vendor specific - sometimes just a LED, sometimes a
16	Backlight	more advanced system

For a simple PC LCD interface which is compatible with a lot of the LCD driver
software running on a PC  (this is often reffered to as "Winamp" wiring, but
as far as I am concerned, it is just the simplest correct answer)

LCD 	LPT pin
1	25		Gnd
2			+5V	power can come from floppy connectors
3			GND
4	16	(INIT)
5	14
6	1	(!STROBE)
7	2	DB0
8	3	DB1
9	4	DB2
10	5	DB3
11	6	DB4
12	7	DB5
13	8	DB6
14	9	DB7

For addtional displays
6	17	(!SELECT)
6	14	(!AUTOFEED)

Additionally, a simple keyboard can be added with the following circuit:

       -+-
GND ---o o---+---[R10k]--- +5V
             |
             |
           Signal

with signal being pins 10,11,12 and 13.  More than four switches will require
a more elaborate setup.  The pullup resistor may not be required in all cases,
giving an extremly simple setup.


Crazy big LCD:
--------------

Out of an old timeclock device, I salvaged a four line by forty display that
is implemented with two separate HD44780 devices and two enable lines:

1	\
2	Tied together	- GND?		25
3	Contrast			via pot to GND
4	+5V?				-
5	RS				16
6	R/W				14
7	E for top?			1
8	E for bottom?			17
9	D0				2
10	D1				3
11	D2				4
12	D3				5
13	D4				6
14	D5				7
15	D6				8
16	D7				9


A large amount of the information on this page is identical to the LCDproc
stuff (no, not all of it was taken from there - much I already had before I
found the nice collection of setup information available in the LCDproc
documentation: http://lcdproc.sourceforge.net/docs/0.4.4-docs-html/drivers.html