20x4 LCD Display with I2C serial interface

Have one of these, works fine. First time (well once I understood which pins support I2c - another thread on that). But I want to know whether I need to tell Espruino that it's 20x4, and if so how?

This code

I2C1.setup({scl:B6, sda:B7});
var lcd = require("HD44780").connectI2C(I2C1);
lcd.clear();
lcd.print("Testing 123 123 123 123 123 123 123");

Prints "Testing 123 123 123" on the top row of the display, then there is a blank row, and then I get the final "123 123 123 123" on the third row. As expected ?

Is the a way to specify which row/column I want a piece of text to start ?

Pat