Programming the ZX Spectrum’s bitmap display

Article excerpt

Michael Martin writing on the Bumbershoot Software blog noting that the ZX Spectrum does not in fact have a text mode, and instead provides only a bitmap screen that its system ROM sometimes wraps in a character-oriented API. That API is quite powerful, but we also have direct access to the bitmap memory. Today, we will discuss that memory and how to work with it. The other relevant fact about the ZX Spectrum is that this bitmap mode is all we have. The platform got many finely-animated games over the years, so we will also cover some techniques for sprite-like behavior without actual sprites. See the post for the exact configuration and on how it’s used here.