ZX Spectrum Screen Memory Calculator

The ZX Spectrum Screen Memory Calculator provides two useful ways to explore how the Spectrum's screen is stored in memory. The Character Cell and Address Lookup calculator lets you enter a PRINT AT line and column, or a screen-memory address, and see the corresponding display-file and attribute addresses. It also includes the two INPUT lines, 22 and 23, with a warning when they are selected. The Pixel Position calculator works with the coordinates used by PLOT, allowing you to enter an X and Y position and see the screen byte, attribute address, character position, pixel bit and mask. Together, the two calculators make it easier to see the relationship between the Spectrum's screen coordinates, character cells and the addresses used to store them in memory.