I guess this is my night to post to the PICLIST!

I have a clock project that needs to display hh:mm:ss on a largish LCD
display.  I have found a nice one at a good price (surplus -- no docs or
markings of any kind) and got a sample to prototype.  It is a bare (no
driver chips) LCD in a kind of huge DIP.  It would be perfect for my
purposes.

I sat down tonight to begin probing it for the pinouts when I realized
that, while I have done any number of HD44780-based projects, I had no
idea about driving a "raw" LCD.

1)  What voltage range is typical?  Is 5VDC sufficient?

2)  What about polarity?  Can these things be damaged by reverse
polarity?

3)  What about series resistance?  I know these are *very* low amperage
devices, but do I need a series resistor with each segment for some
reason?  If so, what size?

4)  Is there going to be a chip-wide contrast pin on this thing, or is
that up to the hardware that drives it?

I did a search with a couple of the search engines, but could not find
any info on any 'raw" LCD's.  Any help or advice is appreciated.

Michael

REMOVE THE .NS (NO SPAM) FROM MY ADDRESS TO REPLY
*************************************************************************When th
e way of the Tao is forgotten, kindness and ethics must be taught.
Men must learn to pretend to be wise and good.  --  Lao Tzu
*************************************************************************