DESCRIPTION: While arrays of 1000 detectors have been proposed to facilitate x-ray spectroscopy experiments on dilute biological systems at 3 rd generation synchrotron sources, and integrated pixel- preamplifier arrays are being developed to meet this need, no electronics exist to support these detector systems cost effectively. Effective operation requires at least 500,000 counts/sec/pixel, energy resolved spectra, and automated operation. Current data collection electronics must be replicated N times for N pixel detectors, cost $2-3000/pixel without energy analysis or $4-7000/pixel with, and have no ready option for automated operation via computer control. Exploiting the nature of storage ring x-ray production, the applicants have devised an approach which, per pixel, handles burst count rates of 5 mission counts/sec, collects spectra at 250 eV or better, operates fully under computer control, and sells for less than $300, packaged 16 to 32 channel/VXI card. In Phase I, the applicants will construct a single channel prototype, demonstrate their design's functional capability, and explore the engineering issues associated with producing the ASIC circuits required to meet the program's cost and density goals. In Phase II, they would design and produce the ASIC circuits and build a working prototype.