Hatem,

Are you sure?

I read following in the tutorial:

WRITE_2_NIBBLES:
 PUSH  ACC           ;Save A for low nibbleORL DATA,#0F0h ;Bits 4..7 <- 1
 ORL   A,#0F0h       ;Don't affect bits 0-3
 ANL   DATA,A        ;High nibble to display
 SETB  EN 

and not

WRITE_2_NIBBLES:

PUSH  ACC           ;Save A for low nibble
ORL DATA,#0F0h      ;Bits 4..7 <- 1
ORL   A,#0F0h       ;Don't affect bits 0-3
ANL   DATA,A        ;High nibble to display
SETB  EN 

as you claim...

or am I too hasty in my remark? (I did not actually "bit" verify the operations, and my assembler is too "rusty" to immediately spot the consequences if the different routines...)

regards
Patrick