Even though EVERY tutorial on the Internet says that you need to connect the contrast pot to 5v, for some reason, the pin3 is powered internally for this specific LCD, so all I had to do, was to not connect the pot to 5v.
It should have worked either way.
Bill Perry will probably know whether panels exist without the pullup. Obviously those displays need to have a pot instead of a single resistance.
I haven't run into any.
If the manufacturer of the board has followed the "Drive Voltage Supply Example" shown in Figure 21 of the HD44780 data sheet then the 'pullup' function is provided by a ladder network of four or five resistors providing the various voltages needed by the display.
NOTE that that above mentioned figure shows the lower end of the variable resistor going to -5V which is required for extended temperature range displays. It can be (and normally is) connected to GND for standard temperature range displays.
Don