Hi Tony,

>  I am having trouble initializing my 2x8 optrex lcd w/hd44780a
> controller
> in 4 bit mode.I have tried everything I could glean from the FAQ's but
> it just
> does'nt shift to 4 bit mode and all subsequent writes cause the cursor
> to move
> two places.In the simulator the write routine 4 bit writes upper
> nybble,lower
> nybble with no extra loops and the character printed bears no relation
> to the
> one I was attempting.I am using bits <4..7>b for data & bits <1..3>b for
> control
> The rs & r/w bits are output with enable low then enable is toggled high
> and the
> 4 data bits are output then the enable bit is toggled low.

You might have a look at the following I did in Pascal just
to get an idea of the steps to take.  The plan is to write
the reset to 8 bit mode comand to the display 3 times as
recommended in the data sheets and then send the set to
4 bit mode command once.  All 4 of the above were single byte writes
after the last one then you start to write nibble/nibble.

http://www.ip.co.za/people/kalle/project.htm#lcd

Cheers     *<<<-|
--
Kalle Pihlajasaari   kalle@ip.co.za   http://www.ip.co.za/ip
Interface Products   P O Box 15775, DOORNFONTEIN, 2028, South Africa
+ 27 (11) 402-7750   Fax: 402-7751    http://www.ip.co.za/people/kalle