China DOS Union

I have a 586 machine. The original setup was dos6.22+norton 8.0, and using speedisk was fine. But later I installed dos 7.10, and every time I use speedisk, it says
system forbids memory access
system halted
press ctrl+alt+del to restart your computer
or look lock/?
My config.sysy is: autoexec.bat:
xms,ems, loaded start ctmouse,
dos=high,ems,umb ndd /q
shell=ndos.com set djgpp=c:\djgpp\djgpp.env
........ set symantec=c"\symantec

Machine specs: P1200hz,32mb,2gb,
Three questions:
1: How do I remove this??
2: How do I disable it forever, so after booting, at any time I can access speedisk, unerase, diskedit..........
3: (last resort) How do I change dos7.10 back to dos6.22?? Under dos7.10, the memmaker, defrag, etc. from the original dos6.22 can no longer be used,

Also: where can I download Prolog software and tutorials...

Thanks!
Hope an expert can save me!!
Thanks!!

lbyoopp@yahoo.com
lbyoopp@mymail.com.cn
65587603

It is not some “forbidden memory access,” but rather “forbidden direct disk access”!!!

The root cause is that the disk tools you are using are too old. Please upgrade to the latest version! For example, upgrade from Norton 8.0 for DOS to Norton 2002 for DOS. Because these old tools, like DOS 6.22, do not support long filenames or large hard disks, they may damage the hard disk, so these disk operations are forbidden by DOS 7.1 in order to protect large hard disks and long filenames! Under DOS 6.22 there is precisely no such protection at all, so if you use DOS 6.22, your large hard disk and long filenames may be damaged by this old software at any time (if your system has a large hard disk and long filenames). So upgrading the software itself is by far the best solution.

Or, when downloading the newer MS-DOS 7.10 full installation edition, when the installer prompts whether to enable “direct disk access“, choose Yes and everything will be OK. That way DOS 7.1 will no longer check these direct disk operations (did you fail to read the prompt carefully when installing DOS and casually choose No, causing DOS 7.1 to automatically check direct disk operations?)! Or use a manual method, for example enable direct disk access for drive C: LOCK C: But note that in that case these old disk tools may damage long filenames and large hard disks! So the best method is still, as stated above, to upgrade the software itself.

Understand now?

Thanks. I have one suggestion: it seems the pc-dos 2000 in the new dos cannot be downloaded...

One more question:: what is the difference between programming in DOS protected mode and programming under pure DOS??
How does cwsdpmi act on the system? I checked with mem/c, and there doesn't seem to be any difference??

..................................Thanks!