(MS-DRG) Software - National Technical Information Service

Using the alternate interfaceThe alternate grouper control program, (D280CA) operates the sameas the standard grouper control program (D280CN) except that itdoes not contain any macros and is written to be re-entrant, so itshould run in a wider variety of mainframe environments. Whereasthe standard interface uses GETMAIN to obtain a 20,000 byte workarea, the alternate interface requires that the calling program providethe work area. It must do so by providing two additional addresses inthe list pointed to by general register 1 (see table 4–1.)Table 4–2 gives the additional work area parameters required by thealternate interface.Table 4–2. Work area parametersOffsetFull word pointer to...72 A buffer of at least 20,000 bytes.76 4-byte binary (PIC 9(8) comp) field containing the actuallength in bytes of the work area. The value of this fieldshould not be less than 20,000 bytes, though largervalues are acceptable.To use the alternate interface, substitute D280CA for D280CN andprovide these two extra parameters. See the COBOL program ALT-TEST, provided in the source library, for an example of how to set upa work area and pass it to D280CA.Assembler programmers should note that the length of the work areais not given in the full word at the offset 76 from R1 but rather apointer to the full word containing the length is given at offset 76.Sample JCL for running ALTTEST may be created by modifying theJCL shown in figure 4–1. To modify the JCL, change all occurrencesof COBTEST to ALTTEST and change D280CN to D280CA.10/10Using the grouper with higher-level languages 4.9