šļø Amiga Knowledge Base
65,174 curated entries on demos, software, hardware and history of the Commodore Amiga
HAM
HAM (Hold And Modify) is a unique display mode introduced in the Amiga's Original Chip Set that enables the simultaneous display of all 4096 colors from the 12-bit color palette. Rather than storing complete color values for each pixel, HAM mode encodes pixels as modifications to the previous pixel's color components, holding two channels while modifying one. This technique dramatically reduces memory requirements compared to true 24-bit images while achieving photorealistic color depth, though it introduces characteristic color fringing artifacts when rapidly changing colors horizontally. HAM was revolutionary for desktop video and image processing applications, allowing the Amiga to display high-quality photographs long before other home computers could achieve similar color depth.