Rainbow Memory Extension

This document consists of a four-page set of schematic diagrams detailing the 'Rainbow Memory Extension' circuitry. The sheets cover the following functional areas:

• Sheet 1: Data buffer and parity generation/checking circuitry.
• Sheet 2: Bank select logic and RAM control buffers.
• Sheet 3: Refresh counter logic and DRAM address multiplexing.
• Sheet 4: RAM chip array configurations (using 4164/41256 DRAM chips).