Strange command-line printing behavior

I have just reinstalled IP 6.22A on a new Windows 7 PC, and see some strange printing behavior in the History/Command-Line. I want to print the value of a global variable, Gwidth, that happens to have value 2. It appears like:
print Gwidth
  2int Gwidth
printf  "%g\r", Gwidth
  2intf "%/g\r", Gwidth


What is also odd, is that when I copied and pasted the History lines into the above extract, it appeared correct. I edited it to show what my PC monitor displays. It appears that the monitor output result is the echoed print command, over-written by the variable value. Has anyone else encountered this?
This is due, I believe, to a buggy Windows video driver that does not scroll properly.

I added a workaround which requires a nightly build from 2011-08-02 or later. Here is the description of the change:
Quote:

Added "SetIgorOption ScrollingMode=mode" to allow you to disable the use of ScrollRect (Macintosh) or BitBlt (Windows) when scrolling text or tables. This is rarely necessary but can be used if your video hardware causes garbled scrolling. mode=0 is the default and enables ScrollRect/BitBlt. mode=1 disables ScrollRect/BitBlt.


I've attached a zipped Igor procedure file which disables the use of BitBlt (Windows) or ScrollRect (Macintosh). Place this file in the Igor Procedures folder in your "Igor Pro User Files" folder. To find your your "Igor Pro User Files" folder, choose Help->Show Igor Pro User Files. Once you have done that, Igor will automatically load the file and execute the IgorStartOrNewHook function at launch time. This will set ScrollingMode to 1.

REMINDER: This feature is not in IP 6.22A. It requires a nightly build from 2011-08-02 or later.

Set Scrolling Mode To 1.ipf.zip (1.12 KB)
Howard,

I tried this and it does not solve the print scrolling problem. As I mentioned in a follow-up post to the mailing list, the scrolled results disappear after an IP window refresh, but then re-occur. This is still happening.

Is there any way to monitor from Igor the status of the scrolling mode?

Steve
Here is another interesting observation. I am running with dual monitors, and when I move the IP window to an older smaller (NEC) monitor the print scrolling problem is not there. Dragging the IP window back to the "better" Dell monitor cause the problem to reappear.

I will look into alternate drivers for the Dell monitor.
Quote:

I tried this and it does not solve the print scrolling problem.


I'm not sure precisely what you mean by "this". Test it by manually executing:
SetIgorOption ScrollingMode=1


Then do your Print test. This "should" solve the problem.

Is there any way to monitor from Igor the status of the scrolling mode?


Yes:
SetIgorOption ScrollingMode=?; Print V_flag


Quote:

I will look into alternate drivers for the Dell monitor.

If you have a Dell-specific driver then it could be the culprit. Otherwise try updating the driver for your video output card or circuitry rather than the monitor. Also look in the Display control panel for any or driver-specific video settings (e.g., acceleration). Try turning them off.


After I followed Howard's instructions correctly, the above solution he provided did indeed correct the print/scroll problem I was having.

I installed a IP6.23 nightly build (10 May 2012) along with Set Scrolling Mode To 1.ipf, and I no longer get the over-writing artifact in the History from command-line print statements. In case other IP users new to Windows 7 encounter this problem, this solution may help you too.

The exact cause of the problem is still puzzling, and its occurrence depended on several factors too complicated to describe fully here. The bottom line is that WaveMetrics came through again.