Thanks Edgar and Peter for new suggestions.
I hope the following makes some sense.
In MS dos I compile and link my code into an executable.
Since 2012(new comp)I must use DOSBOX to run it, I still don`t know why,
but it is ok.
I know I need new versions, but my last project(since 2010)contains
about 350 functions with a total of 43000 lines of source code.
Almost every function contains calls like rect() circle() textout()
masked_blit() etc...that I need for testing.
Do they still exist in newer versions, or is it possible to adapt them
to new versions?

Because I soon need a new comp will it be wise to stay with djgpp and
allegro or is MinGW a better option for my project(human intelligence chess)?
and the many programs before 2010?

Hope to hear from you.
Peter K.

Unless you have a DARN GOOD reason to use DOS, do not use DOS. It was being phased out twenty-five years ago.

Use a Windows compiler with the latest version of Allegro 4. 95% of your program will work without changes. [Allegro 5 is the one that changed the API.]

If you insist on using DOS, you will pay the price for using an unsupported, obsoleted operating system. You might as well be programming on a CP/M machine, a Tandy, or an Amiga.

Or for nostalgia. I do miss DOS programming sometimes. That was around the time that I probably got the most enjoyment out of coding, especially once I discovered DJGPP and could forget about near and far pointers.

edit: Now that I think about it, I think it was discovering Allegro that put me on to DJGPP.

You probably already know this but I'll say it anyway: the experience of compiling with MinGW in a Windows terminal prompt is almost identical to using DJGPP in DOS - the compiler is still gcc and you will be using make (probably). So you have nothing to fear!
Going from Allegro 3 to 4 is not nothing, but you will find it very familiar. Originally there was Allegro for DOS, later there was WinAlleg for Windows, XAlleg for Linux etc. These were all brought under the same roof and that was Allegro 4. Its API was the same as Allegro 3, although some more things were added from 4.0 to 4.4.
By the way, what editor do you use? If it's a DOS one you might need to change but I am sure there will be a Windows one which is similar.

My guess is that Amarillion would know the Dutch word for 'constrained' if we asked him

Good luck Peter K, I look forward to seeing you next post!

to Peter Hull: I think Amarillion meant: constrained PERSPECTIVE ?
Like tangled up in some idea and never getting there, or anywhere ?
I hope he will read the previous post and could send a creative reply.
I like your responses.

to Chris Katko: A forum signature, OK, I did not know. I`m new in this..
Imagine one line of text containing 20 words (values/meanings/etc.) with a clear message for people to read. That could arise different interpretations of that text for people to create computer programs for people to read and incidentally for machines to execute, etc.
In my programming I create (too)long functions(like 200-500 lines).
I know the risks.
I cannot cut them into separate ones. It becomes too complex.
In my view you cannot interrupt thinking.
Let me hear from you..

Peter K.

If your code is valuable to you, port it to MinGW-W64 and GCC on Windows using CodeBlocks with Allegro 4.4.3GIT . That will be the LEAST trouble with the MOST gain for you right now.

Then in the future I would recommend you write all your programs using Allegro 5.