DumpMarvel main menu

The first thing you see is the menu of what's in the dump. Unlike the standard SYSUDUMP, you're already seeing useful information, all in one place. You can see the abend you've had, the PSW where it occurred, the general registers as well as the addresses of a number of control blocks that may be of interest.

At the top of the screen is a reminder of the commands you can enter in the command line and the line commands you can enter in the prefix area of any line (e.g. "S" to select)

Check out the PSW

By selecting PSW from the menu (or entering the PSW command), we can see the program storage at the PSW. No need to go through multiple find steps - we go straight there. The OPP command (not shown here) expands the instructions at the PSW so that you can see what instructions you were executing - this display also shows you what is in all the registers.

Control blocks

You don't have to wade through pages of control blocks to find the bits of the dump you're interested in. But, when you do need to look at your MVS control blocks (such as a TCB), it's as easy as typing "TCB" in the command line or pointing and shooting at the TCB you want on the menu screen.

Paper Clips

If you're old enough to remember dumps printed on lineflow, you've probably never got over the loss of paper clips or sticky notes stuck into interesting bits of a dump. They're back and even better! DumpMarvel's "tags" let you label as many parts of your dump as you like and jump between them just by clicking the tag's name on the "Tags" menu. Here we have 5 tags set - the first two point to the start and end of our "Scan routine", the next points to our working storage, the next to some ISPF panel areas and the last to our command analysis routine. No need to keep going back to the menu or digging a value out of a register or writing down addresses - tags manage all of that for you.

Back to the assembler code

DumpMarvel can disassemble any machine code you point it at, turning it back into usable Assembler code which can be saved using the SAVE command. That means you can even debug a program whose source you don't have access to or that you have lost. Note in the example below how DumpMarvel has successfully distinguished between executable instructions and non-executable constants.