You are right. The registers should be set before EN is brought high. You are also right in that it probably will work (and does) with slow 8051's--if I remember correctly, I wrote the LCD tutorial in 1998 so obviously slow 8051's were certainly more the norm than they are today, hence no mention of delays with higher-speed MCUs.

In my defense, I wrote the RTC tutorial after I had written LCD code for a consulting project in which the client provided a photocopy of the datasheet for the LCD that was used in the project. The order in which the tutorial indicates I/O lines should be set reflects what was stated in that datasheet. Since the datasheet instructed me to do it in that order--and it worked --I had no reason to doubt its accuracy. I do seem to recall that the datasheet was written in poor English, though, and it's entirely possible that what was written was not what they meant to say. It's also entirely possible that I misunderstood what they had attempted to write.

In any case, I corrected that error in the RTC tutorial in an offline version some time ago. I'll make a point of fixing the HTML version ASAP.

Regards,
Craig Steiner