Re: [Freedos-user] Could the MDADEBUG TSR be used to find this FreeCOM bug?
On Fri, Jul 3, 2009 at 4:34 PM, Shane Baggsshan...@hotmail.com wrote: I've posted before about the four machines I'm running FreeDOS on -- One is exceptionally well behaved with FreeDOS 1.0 and another is exceptionally quirky. In particular, I've been experiencing the FreeCOM bug where the command prompt returns without executing the command. Nobody knows for sure when this happens, but it seems to happen in response to a general protection fault that goes unreported, as 4DOS reports a general protection fault under the same conditions. I just discovered MDADEBUG, available from Marc Alexander's page http://www.onr.com/user/mda It's a debugger as a TSR. I've got a machine where the bug can be triggered on a fairly regular basis. I've been able to trigger the bug, then press ctrl/alt/F12 and get the debugger. Now that I've got the bug and the debugger, what should I look for? It's probably a good idea to use the debugger to log what calls to int 0x21 occur between calling a command and the next prompt that occurs. We want to know exactly what FreeCOM is doing so that we can hopefully find out what is happening differently than in a normal instance. Lauren found her dream laptop. Find the PC that’s right for you. -- ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user -- ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Two non-bug reports.
First non-bug: LFN-EN utilities don't work with my FAT32 partition under FreeDOS. After examining the source code, it turns out that the logic was coded in 1999 when the only DOS that could handle FAT32 was MS-DOS. When run under FreeDOS, the utilities assume no FAT32 support, so they misidentify the partition as FAT12. For test purposes, I made a version that accepted the vendor byte FD (FreeDOS) instead of FF (MS-DOS) and it worked, but anything used in production would have to use a different method to determine whether FAT32 is supported (FreeDOS comes both ways, and there are several DOSses today that support FAT32.) There is similar logic that determines which versions of DOS require volume locking (MS-DOS 7 or later.) Fortunately the LFN-EN utilities are open source, so someone could fix this. A reliable FAT32 test method is to check whether a common subfunction of Interrupt 21h, Function 73h (FAT32 extensions) is supported. I disregard any method that works per DOS version. Users apparently don't want technical details on the Freedos-user list however. Regards, Christian -- ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Minor nit: Norton Utilities slow with FDAPM APMDOS; FDAPM APMOFF fixes.
Norton Text Search (ts.exe) prints about four characters a second when FDAPM APMDOS is running. Setting FDAPM APMOFF fixes this. This may also affect other Norton Utilities. I suspect it's because FDAPM hooks an interrupt for power saving use that Norton was already using for something. Try FDAPM APMBIOS. Does it still affect the program's performance? APMDOS hooks too many interrupts. Regards, Christian -- ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
[Freedos-user] buggy djgpp with freedos.
Maybe someone can figure this one: installed freedos base on an old dell(ten years);installed djgpp with rhide; acted very buggy and refused to compile even a hello world; rebooted with 'himem' option, and now it compiles and executes. However, I then tried a larger program with eight functions, and it too, compiled and 'created' with no problems. Tried to run the executable and got this: page fault at 0x1ba1;error 0006; I'm sure that the program partially executed since the mouse cursor was left on the screen, and my program involves a mouse event handler. The program involves calls to 'int86', but this should not crash anything, since even the NT dosbox allows this. Was I deluded all this time into thinking djgpp was 'backward compatible' with a true dos system, and I just never strained the high memory aspect until now? --kurtwb2...@gmail.com. -- ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
