Flexer, Robert J.

A Building Block Approach to Color Graphics Tools

Excerpt documents the design rationale and implementation of the CAT-100/C modular video-graphics system; it describes a two-board S-100 bus implementation with a 32K dedicated frame buffer (expandable to 256K), a real-time analog-to-digital input (4-bit), D/A output and NTSC color generation, serial data paths and three external video streams, and facilities for lightpen input and photographic triggering. It details buffer formats and page/window addressing, two-port buffer timing guaranteeing clean display, text mode capacity and clock options, and palette and control-register functions for image and color handling.