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3 - Upgrade path
Ideally, for the time being you need to supply program versions for both OS1 and 2 until everyone has upgraded. The new system provides a make option (make os1) to compile an old-style .FXE file. To make an OS1 .SEB, you can run 'make seb1', after first making a copy of your <program>.atts file and renaming it <program>_os1.atts. However, while this will include the GUI code in your application (required for OS1), it will be the OS2 GUI code, which you should be aware of.My recommendation for now is to do a final compile of each of your OS1 programs before you upgrade. The effort of switching back and forth will be annoying and error-prone, and shortly there won't be any OS1 programs out there (can you remember Windows 3.1? How about 2.0?)
Of course, one simple upgrade method is to set up OS1 on an old computer for emergencies, and then upgrade your main computer to OS2. Besides making the upgrade path straightforward, you are protected in case of an emergency.
This column's program is an upgrade of the image viewer program covered in a column from August. It's especially useful, as one of the OS2 changes is in how the image modes work. If your code has been depending on them, run the program to see the changes. As well, the included SEB runs under OS2, so if your ebm is still in OS1, you might enjoy running it just to see the 'requires newer OS' warning in five languages.
Now on to the nuts and bolts of upgrading...
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