Hi All, A number of users have reported that JDEbug hangs on Windows 2000. My office machine was just upgraded to Windows 2000 SP1 and, you guess it, I am now experiencing the same problem. In particular, JDEbug generally hangs on the first attempt to start it. I can get it to start and stop at a breakpoint by increasing jde-bug-sio-connect-delay but then I get a hang when I issue a Continue command. Some users have reported that installing SP2 clears up the problem. So I took a look at SP 2 and found that it includes a fix for the following bug: ==================================================================== Console STDIN And STDERR Redirection May Cause Deadlock in 16-Bit MS-DOS-Based Program The information in this article applies to: � Microsoft Windows 2000 Professional � Microsoft Windows 2000 Server � Microsoft Windows 2000 Advanced Server SYMPTOMS When console STDIN and STDERR are being redirected in a 16-bit MS-DOS-based program, the program may stop responding (hang). For example, if a 32-bit Windows-based program uses two pipes (for read and write) and redirects these pipes as console STDIN and STDERR for data communication with a 16-bit MS-DOS-based program, and the 32-bit Windows-based program and the 16-bit MS-DOS-based program are interdependent for data transfer, a deadlock may occur. CAUSE This issue is caused by a problem in Ntvdm.exe. ===================================================================== This bug sounds suspiciously like what is happening in the case of the communication between Emacs and JDEbug. Both are 32-bit programs. However, I can't help wondering if the bug applies to communications between 32 bit programs as well and was just first encountered when somebody tried to use a Windows program with some old DOS command-line utility. Emacs appear to JDEbug as a command-line utility. If this is the case, it is probably fruitless to try to find an Emacs fix for the problem. (Well, actually using sockets exclusively for communications between Emacs and JDEbug might work.) Anyway, installing SP2 does appear to offer an immediate solution to the problem. That's what I plan to do. - Paul
