The costs of owning and operating cotton gins change continuously because of the variability in machinery prices, interest rates, energy prices, wage rate, and annual ginning volumes. Gin owners considering equipment or operational changes and others evaluating the feasibility of entering the ginning business require economic information on the impacts of these factors if they are to properly evaluate the alternatives they face. There is also a need for regularly updated estimates of the costs of owning and operating gins at current prices, interest rates, annual volumes, and labor costs. GINMODEL, a mainframe computer model developed by Dale Shaw, can be used to estimate per bale ginning costs under a range of conditions. This paper reports progress toward adapting this model for use on micro computers. It also reports on efforts to evaluate size and volume economies using GINMODEL. Findings to date are reported.