z390 Support in VisibleZ

I envisioned VisibleZ as a teaching tool for assembly language – I wanted to force students to deal with object code as a way to learn the assembly language. With VisibleZ, after writing a few bytes of object code, you can watch the effects of a given instruction on the state of the machine, and in the process learn a thing or two.  Or, you can simply step through the hundreds of pre-written program snippets that comes with it.  I’ve tried to make it easy to write program snippets – two hex characters represent a byte, with bytes separated by spaces – all in a text file. No need to write a large program to get some experience with an instruction.

A few months ago, James Cray, one of the contributors to  z390, the Portable Assembler and Emulator Project , suggested it would be nice to be able to load z390 object modules into VisibleZ.  If you’re not familiar with that project, and you don’t have access to a mainframe, you should check it out.  Using z390 you can write large, well-developed assembler programs and run them on your pc.  It also supports Cobol and CICS!

I didn’t want to want to change my original file format, but I decided to take James’ advice by providing some support for z390.  I’ve just posted an experimental version (executable jar / codes.zip -code snippets) of VisibleZ that will take the assembler listings produced by z390 and scrape off the object code and format it it to run in VisibleZ.  You will have to install z390 separately and tell VisibleZ where it lives on your machine.  After that you can assemble a program and run your program, all within VisibleZ.

The experimental version runs on Windows only.  If there is any interest in getting this to run on Linux, let me know.  I’ll remind you that VisibleZ still has limited support for QSAM files – 80 byte records and a limit of three input and three output files.

3 thoughts on “z390 Support in VisibleZ”

  1. I find VisibleZ useful when using Z390. I use it to debug a program. One complaint. I can’t save settings from session to session. Thx for the work.

  2. I just sent you an email and now I have more information. I’ve installed the experimental version of VisibleZ. I am running Z390. I have followed directions for installs. When I step through my Z390 assembler program I see assembler instructions being skipped. These instructions are in the CSECT macro. ie, the instructions in order are STM, and BAL to location 68. Locations 68 and 6C instructions, ST and ST, are skipped, and the instruction LR at location 70 is executed. I included this information to help. I’ve more. I can provide an email attachment with what I find. Thx.

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