z390 Portable Mainframe Assembler

z390 Portable Mainframe Assembler is a free and open-source application written in Java that offers both a graphical and command-line interface for assembling, connecting and executing programs via simple commands. The downloaded package includes the source code as well as a demo. Users can type ASMLG demoDEMO to assemble and execute demo.mlc.

It offers support for common macros, such as READ, WRITE, CHECK and POINT (random), OPEN, CLOSE, DCB, PUT and GET (sequential), SPIE, SNAP, ABEND and STAE, STIMER, TIME and TTIMER, FREEMAIN and GETMAIN, WTOR, POST, WTO and WAIT, along with RPL, ACB, PUT, GET, POINT, MODCB, TESTCB and GENCB (VSAM). Sequential and random file access can be done via EBCDIC or ASCII. The supported structured macros are IF, ELSEIF, ENDIF, DO and ENDDO.

The graphical interface of z390 Portable Mainframe Assembler features popup menus (File, Edit, Options, View, Help), a log area that can be scrolled to view the output of each sent command, and a status bar that shows batch I/O and other status details. Also, users can customize options when it comes to the window location, size and font, as well as submit, monitor and cancel batch commands.

The tool is compatible with Windows, Linux and Mac OS X. However, because it hasn't received updates for a very long time, it doesn't work with the latest version of the Java Runtime Environment. The developer recommends Java 6.0_30.