why serial?
#1, I only have 9 pins to deal with
#2, I think managing data with it is somewhat easier
#3, now a-days they have USB, and serial port is closer to a USB port than a parallel port in terms of operation.
#4, I use Qbasic to send data to the ports, and during debug time, the parallel ports take longer than serial ports if I mismanage the busy signal.
#5, I'm struggling either way.
I tried the parallel port, but I somewhat have more success with it, but not enough.
Using serial or parallel port (I dont care at this point), I want to be able to send data to an LCD, and make the computer wait until the LCD is finished processing the last instruction.
With my LCD, I think pin 5 is the R/W pin. If it is enabled, data is extracted from the LCD. Otherwise, data is sent to the LCD. There is also a clock pin.
According to my LCD manual, when R/W is set to READ mode, data bit 7 must be clear for the LCD to not be busy. At this point, the computer needs to know it can continue.
In other words, I want to send data to the LCD without entering delays in my program on the computer. Yes, I'm going for speed too, because the faster data can go to the LCD, the better.