I have a client who has legacy systems running on and old dos based paradox platform. The system runs under DOS and requires 600k of Ram.
Recent windows updates on XP and Windows 7 have been causing the available memory to drop below 600k.
There are some financial implications to doing a complete upgrade away from the DOS based systems to windows. The consultant for the legacy apps is saying that we should have all XP machines. I don't see that as being viable for a number of reasons
- Incompatibility with modern apps such as office. - Security issues due to the end of life of XP
I tried running XP in a virtual box on a win 7 pro 64 bit system. That never worked right because of the interactions with the legacy systems and peripherals. I have gotten things to work after a fashion by using 32 bit versions of Win 7,
My advice is that trying to remain on Win XP would be a disaster. This particular industry is subject to a number of federal and state regs and laws regarding privacy. I'm just trying to double check if there is any other alternative. I was thinking of some type of citrix server to show the legacy apps in a terminal window but that seems like it would be difficult to implement.
The alternative I'm proposing is to try to migrate individual components of the system one at a time. That way, we will take one piece of functionality at a time and bring it into the 21st century.
I wonder if other Virtual PC software might allow you to virtualize this app. VMware seems to have the widest selection of options for virtual hardware settings. Have you tried anything other than Virtual Box?
@martinibuster - the problem is that 16 bit apps running under windows can't see all the memory. They can only see what you see in a Mem /c command in a command window. For the version of paradox being used here, it requires a 600k free block.
The problem is that, in my opinion, were are delaying the inevitable by trying to continue to patch windows to work with an ancient app.
I'm going to try a couple of things tomorrow to try to increase memory. If I find anything that works, I'll post it back here.