Thanks so much. I downloaded QB64 and looked at the saveimage and printimage examples you linked me to. Haven't unzipped it yet though. Looks like there is reason for hope here after all these years. Believe me, this simple chore seems to not be solved very well. There are graphing programs but they are so burdensome as to make them not useful.
It will take me some time to get in the mood to start working with a different environment than the GW one I have used all these years to investigate my scientific interests but if it is good, I will do it. After finding that VisualBasic was not a programming environment but a GUI development environment I didn't think there was hope for Basic.
Many thanks - Ken
You're welcome. I hope it works out for you.
QB64 aims for QuickBASIC 4.x/QBASIC 1.x compatibility, but it should hopefully work for GWBASIC code too, to the extent that QBASIC is backward compatible with GWBASIC.
If, for some reason, QB64 doesn't work out for you, you should be able to run GWBASIC in DOSBox and get the PrintScreen captures that way.