before Windows or GUI's came out, MS-DOS was king of the hill
When MS-DOS was king of the hill... it easily ran on an 8088 or 80286 processor with 16 meg ram and 20 Meg harddrive. Floppy disks held 128 K of data.

My new laptop has 8 gig of ram, 1 terrabyte harddrive.

Many times (not always, though) execution speed of code is paramount. I would venture to guess that the final code produced with Flowcode 5 is many times slower and more bloated than what PBP produces. PBP is much slower than assembly. Its all relative to what your needs are.

If you want to learn interrupts then start with a breadboard, a couple of pushbuttons, a few LED's and give a go at some of the examples shown on Darrel's instant interrupt web site.

Writing code is a matter of putting together blocks of smaller code that you have tested, learned and gained an understanding of.

One thing I have learned the hardway is ALWAYS do a "save as" before you start modifying a piece of working code. Once you break it and want to go back to something that was working you need a working copy to go back to.

Good luck what ever you choose to do. There are some world class programmers here willing to help with specific questions/examples.