As some of you have observed, z/XDC has gotten a bit sluggish over the years, and unfortunately, I have to agree. So identifying and correcting significan performance issues has become a priority for us.

z/XDC has a very useful Session Log that it automatically writes to spool. It simply records everything that goes on in the display’s top window (the Working Window). But it never includes anything that occurs in Watch Windows. The problem is, that’s where the PSW and registers are normally displayed.

We have added a new shortcut command: LO can be placed to the left of any displayed machine instruction. If that instruction references storage, the locations will be decoded and the one or two locations referenced will be displayed.

Occasionally, a customer may have severe problems with z/XDC, and he may want to revert to an older level of z/XDC. However, due to the design of z/XDC’s installation process, it is not possible to revert to an older level without either reIPL’ing or somehow clobbering z/XDC’s SSCT entry to make it not findable by z/XDC.

No… We can’t actually run your program backwards, but if you want to see where you’ve been, we’ve got a new and easier way of doing that. We can actually make it look like your program is running backwards!

This may be of particular interest when you’re trying to step execution through reentrant code, but your program is in problem state. The difficulty arises, of course, because the System has loaded the reentrant code into key-0 storage, and z/XDC, being in problem state, cannot set breakpoints into the code.

I have just published Z22-1711B that adds support in z/XDC for all the rest of the new machine instructions introduced on IBM’s Z14 hardware. All of the new opcodes, the new mnemonics and the new extended mnemonics are now recognized and understood.

We have just published update Z22-1709E to add to z/XDC release z2.2 support for the new BIC machine instruction.

It turns out that c/XDC users have reasons to issue the LIST LKEDMAP command a lot. This is because:

• It sometimes is the case that the external name of a function differs from its internal name,
• And it is sometimes the case that the user needs to provide a function’s external name in order to load the right source image map,
• And normally, AUTOMAP would do the job for you, but sometimes you might want to load a map or two that AUTOMAP would not be able to realize you might need.

I have just uploaded update Z22-1707B.* It implements the following in z/XDC:

RMODE64 support: When z/OS R2.3 comes out, it will have support for loading modules into above-the-bar storage. z/XDC is now ready to fully support mapping, displaying and stepping through such modules.