This report summarizes the results of a coal-feeder development program carried out by Foster-Miller, Inc., for the US Department of Energy (Contract No. DE-AC21-80MC 14601). The Linear Pocket Feeder (LPF) and the test facility at FMA were upgraded to allow testing of pulverized coals as well as dense coals at pressures ranging to 1000 psi. This represents a substantial advance over the previous design limitation of 500 psi. In addition, methods for controlling leakage from the input side of the LPF by the use of a positive contact seal were developed. Preliminary tests were conducted during the installation and start-up phase of the program. In the conduct of these tests one or several system components were evaluated. Particular problems addressed included uniformity of coal feed into the LPF, coal removal into the reactor, measurement and elimination of gas leakage, and operation of the system at 1000 psi and 5 tons/h. Performance tests designed to demonstrate the operating capability of the LPF and to define and prove its range of operating parameters and its limitations were conducted. Performance tests were conducted with different coal types, sizes, and moistures. Operating data obtained from these tests is given in the report. Successful demonstration of differential pressure capability (1000 psi), throughput capability (5 tons/h), turndown capability (to zero throughput), stop/start capability, capability for handling variations in feedstock, and operational safety and control was obtained. 57 figures, 18 tables.