> Could it be you didn't wait the 100ms at power-up before initialising
> the LCD? Resetting the PIC after power-up would be different from
> a cold power-up if the LCD was talked to too soon. Also, do you do
> the first part of the init code 3 times as recommended?

This is the LCD code I generally use, and it always has worked apart
from that one incident. It must have been something funny about that
circuit (or possibly even the PIC), although the screen did come right
when the speed was bumped up from 4MHz to 16MHz

The Hitachi handbook recommends waiting > 15ms after the LCD's
Vcc reaches 4.5V, and I've found 50ms works OK. If that problem
ever comes back perhaps I can try increasing the pu delay. Take it
as read that the msdelay routine does in fact delay 1 millisecond

;=================================================

         movlw   0xce         ;power-up delay 50ms
         movwf   temp
         call    msdelay
         incfsz  temp,f
         goto    $-2
         call     lcd_init

rest of code

;================================================
;        Initialise LCD screen
;================================================

lcd_init movlw  0x30
         movwf  portd
         bcf    rs
         bcf    rw
         bsf    en
         nop
         bcf    en
         call   msdelay      ;delay > 4.1ms
         call   msdelay
         call   msdelay
         call   msdelay
         call   msdelay

         bsf    en            ;write 0x30 again
         nop
         bcf    en
         call   msdelay       ;delay > 100us

         bsf    en            ;write 0x30 again
         nop
         bcf    en
         call   msdelay       ;delay > 100us

         movlw  0x38          ;2 lines, 5x7 font
         call   write_c
         movlw  0x0c          ;1+DCB = display on, no cursor, no blink
         call   write_c
         movlw  0x01          ;display clear
         call   write_c
         movlw  0x06          ;entry mode set, increment address
         call   write_c

         return               ;return from initialisation

;================================================
;        LCD commands
;================================================

line1    movlw  0x00          ;line 1, column 0
         call   address
         return

line2    movlw  0x40          ;line 2, column 0
         call   address
         return

address  addlw  0x80          ;set high bit of address command
         call   write_c
         return

write_c  bcf    rs            ;write command
         goto   d_out

write_d  bsf    rs            ;write data

d_out    movwf  portd
         bcf    rw
         bsf    en
         nop
         bcf    en
         call   busy
         return

busy     bsf    rw            ;set LCD RW for Read
         bcf    rs
         bank1
         movlw  b'11111111'   ;make d7 an input
         movwf  trisd
         bank0

         bsf    en
rdbusy   btfsc  bflag         ;loop until Busy Flag clear
         goto   $-1
         bcf    en
         bcf    rw

         bank1
         movlw  b'00000000'   ;d7 as output again
         movwf  trisd
         bank0

         return

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