This application requests funds to upgrade existing computing equipment to meet the data management and statistical computing needs of clinical investigators served by the Columbia University GCRC. Specifically, we request $190,275.25 to purchase a Digital Equipment Corporation VAX 6310 with 32-Mbytes of memory, one 622-Mbyte disk drive, TU81A-Plus tape drive, four DECserver 200 8-port terminal servers, ethernet interfaces for the terminals, and associated cables, licenses and media. The disk drives of the VAX 750 are compatible with the VAX 6310 and will be moved to it. The VAX 6310 will provide approximately 8-10 times the processing throughput of the VAX 750, which is currently operating at capacity. The Columbia University GCRC Information Systems unit is the only multi- user computing installation at the Health Sciences campus specifically serving the clinical research chemistry. PHS-funded projects account for over 90% of annual user connect hours and over 95% of annual cpu hours. The compute-intensive data analytic tasks and I/O demand associated with current utilization has exceeded the capacity of the VAX 750. Every system management and user education step has been taken to increase the capacity and decrease superflous demand upon the system. Despite these efforts, the equipment operates at nearly 100% of cpu capacity during daytime hours and almost all processing time is spent in statistical analyses. This request to expand is partly in response to need for the GCRC to serve as the data management center for large multi-center trials and a steady influx of new single center protocols. Furthermore, planned expansion of the GCRC and pending electronic availability of patient clinical data from Presbyterian Hospital are anticipated to increase the number of clinical investigations. The requested VAX 6310 will enable the GCRC to support the growing demand for clinical research computing services and enable the institution to serve the NIH in multi-center trials.