Hello Mark,
I did a lot of program debugging back in the day and recently with the VM/370 system. I used the ADSTOP to set a stop point and the use the CP PER and DISPLAY commands to look at storage and register content. The PER command I used was PER I RANGE nnnnnnn:xx where n is the start trace address and xx is the length of code to be traced. There are a options to step code or let it run to display to the terminal or output to a printer. With DISPLAY you can show storage and register content. You can also get the PER command to do this for every time it traps. There is a whole host of options and commands with PER its worth looking at. Also there is the TRACE command that will trap interrupts and the TRACE PROGRAM is useful to trap program abends and then use the DISPLAY command to look around.
Don¡¯t forget to use the LOAD MAP created by the GENMOD to find the areas where you want to investigate.
Hope this is not telling you stuff you already know !
Regards,?
Martin.
