COMPACT HIGH-SPEED DISK RECORDER

Abstract

In order to meet the high-speed and high-density recording requirements for today's development and testing environments, we are seeking to merge the cutting edge technologies of tiny, high-performance disk drives and field programmable gate arrays (FPGAs) to build a high-speed compact disk recorder (CHSDR). Specifically, we designed, built, and tested a multi-drive controller that handles the interleaving of data to eight inexpensive IDE drives. These drives and controller comprise a "cell" capable of transferring data at 2.45 MB/sec (4 to 5 times the rate of a single drive). Furthermore, these "cells" can be run in parallel (with a single controller interleaving data between the cells). This "tree" effect multiplies the data rate by the number of cells employed. For example, 8 cells (of 8 drives each) can reach nearly 20 MB/second (sustained) and can be built for less than $30,000. The drives we used are the size of match boxes (the Hewlett Packard KittyHawk). These tiny drives hold 42 megabytes each and can withstand 150 Gs while operating. The cell controller is a Xilinx 4005 FPGA. Furthermore, we've designed a 120 MB/sec RAM FIFO to buffer data entering the system (to account for unavoidable drive seek latencies). In short, the compact high-speed disk array is a small, relatively low cost recording solution for anyone requiring high data speed but modest data volume. Missile shots, nuclear tests, and other short-term experiments are good examples of such requirements.