China DOS Union

Hello everyone, I have a question. Because of work, I need to use UCDOS + FoxPro 2.5. Since I'm using an 80G hard disk, I used the DOS from WIN98, then in config I used emm386.exe ram. I downloaded a UCDOS 7 installer from the Internet (a zip file; after extracting it, there is one install.exe plus 15 subdirectories corresponding to installation disks 1--15). During installation, when it prompts to create the autoexec.bat file, it hangs. But on the same machine, at certain times (I forgot under what conditions, seems it was also under DOS), it did install successfully once; sometimes it didn't, but installing under Windows works. It also created some empty directories under c:\. If I test it under Virtual PC, with UCDOS 7 made into an ISO file and placed in the CD-ROM drive, it says
How should I install it? Are there any requirements for installing UCDOS? Thanks.
Also, a question: when booting with the DOS 7.1 boot disk downloaded from this site, after selecting the first option it says
I don't know why, looking forward to your advice.
Also, sorry, too many questions, can't help it. After installing windows98dos + ucdos7.0 + foxpro25, when running FoxPro it always says insufficient memory. Looking inside FoxPro, often only 2**k of memory is left; no wonder it's not enough. The config is set up the same as on another machine, but mem/c/p is still different. After checking, IO.sys and command.com are not the same version. What are the memory requirements for foxpro25/for dos, and how should it be configured? Thanks. The premise is that I don't want to use dos6.22
Thanks.

1. 98 + UCDOS7 should be no problem. Edit the CONFIG。SYS file, and add REM before DEVICE=EMM386.EXE, that is, temporarily disable it as “REM DEVICE=EMM386.EXE".
Or use ”DEVICE？=EMM386.EXE", then when booting, the system will ask whether to load EMM386. If not using UCDOS, choose Y, otherwise N. UCDOS is best installed in the root directory of drive C

2. How is your VPC configured?

3. If conventional memory is insufficient (meaning the 640K of the DOS era), you can optimize CONFIG。SYS and AUTOEXEC。BAT. Post them here and everyone will help you look at them

That message appearing after booting the DOS 7.10 boot disk you used is caused jointly by the following two reasons:

1: A major BUG in Virtual PC!!! It is caused by VPC being incompatible with many drivers / UMB memory. Under real mode or under VMWare, this problem will not occur. This has already been explained in the README.TXT file;

2: The version of the boot disk you downloaded is too old. The latest version of Super MS-DOS 7.10 has tried to avoid this BUG in Virtual PC as much as possible by switching to other drivers (if still under VPC, please boot directly using the IMG image method). Please download the latest version here:

http://newdos.yginfo.net/dosware/mdos71bd.zip

kongling00.ys168.com provides the download