Dual Function Flow Cytometry Software In 32K Words On pdp11
F. L. Battye
The Walter & Eliza Hall Institute
Flow cytometric data from the FACS II cell sorter is handled by a pdp 11-based computer system running under the RT11-FB Foreground-Background operating system. Particular features of the software written for this system over a period of years are: (i) a single operator can run a large series of cell sample analyses quickly without attention to the computer; (ii) hard copy data output is provided automatically at run time; and (iii) higher quality hard copy may be generated and stored data may be examined simultaneously with collection of new data.
Data acquisition and storage in histogram or list mode and display of histograms and correlated two parameter dot plots run as the first priority foreground task. As an extra feature of this program, a sequence of commands can be entered which are executed automatically at the end of each data acquisition; for example, display four histograms and a dot plot, print the percentage of fluorescent cells and make a hard copy.
The background is used for more sophisticated processes on stored data including DNA distribution parameterization, background subtraction, processing of list mode data and extraction of various numeric data. An alternative background program produces pen plots of histograms, three forms of contours and hidden line perspective drawings.
The 32K word memory constraint of the RT11-FB system forces extensive overlaying of programs but, by the nature of the tasks performed, very little loss of speed is apparent to the operator. Moreover, this form of programming makes addition of new subroutines a simple matter, with no additional memory required other than one extra subroutine call in the .MAIN. segment. The system thus lends itself to extensive expansion or adaptation to the requirements of other laboratories.