I will admit the 4bit does make it look more difficult but I pulled the code
from an Application Note from Microchip originally.  I have since change the
code to reflect the suggestions made by everyone.  Ironically, everyone's
suggestions have been very similar leading me to believe that I am on the
correct path.  However, I still have the problem where the LCD display will
not print the letters unless I comment out the goto BUSY_FLAG? as shown
below.  It must be something simple, but I can't catch it.

Thanks for everyone's input, I hopefully will lick this soon.


; Read busy flag, DDram address
 andlw 0xF0
 movwf TEMP
 bsf PORTA, E
 movf PORTB, 0
 movwf TEMP1
 bcf PORTA, E
       swapf TEMP1,0
 andlw 0x0F
 iorwf TEMP,0
 andlw 0x80
 btfss STATUS, Z
; goto BUSY_FLAG?
 nop
 bsf STATUS, RP0
 movlw 0x00
 movwf TRISB
 bcf STATUS, RP0
 RETURN

"Paul B. Webster VK2BZC" wrote:

> John Considine wrote:
>
> > Thanks,  that site is very helpful.
> >> http://www.iaehv.nl/users/pouweha/lcd2.htm
>
>   Indeed it is.  Only complaint I have is that the "Misc. Examples"
> example by Marc Simons is unnecessarily complex (has transistor
> inverter/ time delay circuit that just isn't needed) and he doesn't seem
> to understand why.  Oh well!
>
>   But not on topic - said example *definitely* doesn't use Busy flag.
>
>   I'm sure there is a trap in reading the busy flag in 4-bit mode.  You
> must read the data twice every time (which means you must keep things in
> synch).  I'll bet you are missing out on this or looking at the wrong
> nibble for the flag bit.  Just a guess, haven't sat and analysed the
> code.
> --
>   Cheers,
>         Paul B.