12.The compilation of user defined formulae has been made significantly faster and the addition of MIN and MAX functions allows for more elaborate colouring. See the Internal Colouring examples in the list of user defined formulae. As an introduction press Return as soon as CAL has loaded to draw the default image. If your copy of the CAL files is the same as the set that I distribute this should be the Mandelbrot set in the 256 colour 320x200 mode that is now supported on most computers. If your machine will not use this mode then read the steps below about configuring the program.
All video cards allow for a variety of types of display.
Later systems have been capable of 16 colours and most new graphics cards are capable of displaying 256 colours on the screen at once. Menu choices are made using the cursor keys to change the highlighted option and return to select it. CGA - one of the original graphics standards and only really included for machines which do not support more modern displays or to provide a quick overview of a detailed image. At best you can have four colours on the screen and the image does appear very blocky. However, CGA modes are present on almost all computers, including older portable machines.