Work to resume on DHPOS

[daleadmin]

As you may have noticed I have not had any updates to DHPOS for many months. This is due to my not being able to load the source code for the POS.EXE file into QB7.1. This has been a problem on both my home and work computer.

The theory is that both computers had an automatic update of Windows XP which reduced the amount of memory that could be utilized by DOS. However this is only a theory, sort of like evolution, gravity, or what women really want, so don't hold it against me if proven incorrect.

So I dug up an old XP computer that was not hooked up to the internet and loaded QB7.1 and my source code on that. The result was that it works fine on that. So now I am going to restart work on the "points" feature.

Dale

[cwathen]

Windows Vista/7 (and probably 8 as well) did impose a memory limitation on NTVDM (the emulator which allows DOS and Windows 3.1 programs to run in NT-based versions of Windows). In Vista/7 an old-school program cannot allocate itself any more than 32MB of memory. In previous versions there was no such limit and programs could use as much memory as they wanted. The purpose of this change was to prevent a badly coded oldschool program from taking up all the memory and bringing the system down.

I suppose it's possible that an XP update has changed NTVDM to have the same limitation. However, DOS programs cannot use more than 640K without a DOS Extender/Extended memory support, and generally these don't work under NTVDM anyway.