Animating images on retrocomputers can seem almost impossible if you don't have dedicated hardware resources. In fact, in the early days of home computers, many of them were classified according to the performance of the animation chipsets. It was not uncommon to come across terms such as “sprite”, “bob”, and so on, which were nothing more than “entities” that the graphics chipset made available to the programmer, in order to ensure acceptable performance.

However the text mode of retrocomputers, available on all retrocomputers, often has the ability to dynamically redefine the set of characters that can be shown on the screen.

To take advantage of this feature, a technique for managing graphics, called “tiling”, is described here. This technique is based on text mode and emulates raster graphics by implementing pixel drawing at the single character level. This leaves the maximum resolution available unchanged, while limiting the drawing possibilities.

This short essay describes the theoretical aspects of this modality, the use of a specific program to create tiles and the integration of this modality in an existing library, to create animations with this graphic modality.

This is a short summary of pages related to this topic:

• Basics of tiling
• Animations using tiling
• Convert image(s) to tile(s)
• Demonstration program using midres library
• Memory layout used by midres library