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Converting the Gould-SEL DATAPOOL to Standard Fortran

The Gould-SEL DATAPOOL was a first step towards the Fortran 90 MODULE construct. A DATAPOOL declaration is written in the same way as an ordinary COMMON block, with the COMMON block name /DATAPOOL/. However, the names in the declaration do not occupy consecutive memory locations starting from the beginning of the COMMON. The addresses of DATAPOOL variables are stored centrally in a database maintained by the operating system. The DATAPOOL typically contains thousands of variables, but each sub-program need declare only the names which it uses. Click here to see an example.

The MPX operating system generates a listing to show the contents of the DATAPOOL. A short extract is shown here.

fpt uses this listing to generate an INCLUDE file which represents the DATAPOOL as a standard Fortran 77 COMMON block as shown here. The INCLUDE file is typically several thousand lines long.

The original DATAPOOL declarations are replaced in the code by INCLUDE statements for this file as shown here.

These changes are made automatically by fpt. All DATAPOOL declarations in the entire program are modified.

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