Recent incarnations of BASIC do not require line numbers, and their listings can be more clearly structured. Unfortunately, however, a program written in one new flavor of BASIC won't necessarily run in another, while nearly all the fancier BASICs will still accept old-fashioned line-numbered listings. And the inherent slowness of GW-BASIC has been offset by the speed of today's processors.

BASIC is like giving directions. If you use simple instructions that rely only on freeways instead of local roads, the course may take the traveler a bit out of the way. However, with plentiful traffic signs, the destination can be reached.

If you don't like line numbers, leave out all but the few that actually control flow. Feel free to tweak and enhance the program to your liking. Many people write to us explaining how they have used the S&T program listings as inspiration to explore mathematical astronomy further — and that's the whole point.

But a larger concern looms. Running a BASIC program is becoming nontrivial. Microsoft no longer sells QuickBasic, the full implementation of BASIC that allows listings to be compiled into stand-alone executable programs. Thankfully, Microsoft's BASIC interpreter QBasic hasn't completely disappeared. It's still buried on the installation CD-ROMs for Windows 95 and 98 (find the directory called OTHER\OLDMSDOS). If you don't have either of these, you can download an "OLDDOS" file that includes QBasic from Microsoft's Web site. (Over the years, the location of this file has changed, or sometimes disappeared entirely, as Microsoft occasionally rearranges its servers.)

Download it, unpack it into an empty folder, and you’ll have QBasic and its help file. You're supposed to have a valid licensed copy of MS-DOS or Windows 95/98 to have the right to install QBasic, per Microsoft's Use of Software statement.

If the day comes when Microsoft once again hides QBasic on its Web site, there will likely still be salvation in other BASIC products. You can find other BASIC interpreters and compilers online. To explore the options, see http://basic.mindteq.com/ and http://www.nicholson.com/rhn/basic/#2.

Nevertheless, there may come a day when computers will not run any of the Sky & Telescope BASIC listings without a separately purchased program.

So, Sky & Telescope will continue to offer simple BASIC listings for interesting applications. The fact is that many of our programs, despite their primitive operation, answer the astronomical questions they address more accurately and reliably than some fancy commercial packages do. The treasury of the Astronomical Computing department's programs is an extension of the magazine's mission. Not only do the programs make those articles interactive — they may prove inspirational.