Morgan Davis





The trouble with ProLine was that it was written in Applesoft BASIC, the computer language burned into the ROM of every Apple II computer. It was a funky version of BASIC, too, with an arcane line editing mode. Since ProLine was modularized among a hundred BASIC programs, management became difficult. That inspired MD-BASIC, an Applesoft “processor” that resembled a C compiler, complete with directives such as #include and the whole C-like thing.

MD-BASIC was written in C (with a little 65816). It ran only on the Apple IIGS but produced BASIC that worked on all Apples

MD-BASIC was written in C (with a little 65816). It ran only on the Apple IIGS but produced BASIC that worked on all Apples

MD-BASIC spruced up Applesoft programs by adding modern constructs such as IF-THEN-ELSE, WHILE-WEND, and support for long, descriptive variable names. Line numbers were now something from the Jurassic period, as MD-BASIC let you use nicely named labels. Plus, it output standard, vanilla Applesoft in a highly compact and optimized format, increasing runtime speed and conserving precious memory. Even better, MD-BASIC let you write your programs in a real text editor, so you could format them properly with copious comments. That was impossible with ordinary Applesoft with its frustrating input mode.

GS+ magazine wrote, “Applesoft may never get better, but writing programs in Applesoft just did. MD-BASIC changes the way people think about Applesoft.”

Like most of my programs, I originally wrote MD-BASIC for me, but realized others would find it just as refreshing and valuable. It was one of our best selling products, retailing for $89.95.

Trivia: An intentional quirk of the MD-BASIC manual is I numbered its chapters by tens, like the old BASIC line numbering technique of yore. Seemed clever at the time.

MD-BASIC-3.0.img 800K ProDOS disk

MD-BASIC-3.0.pdf 500K Acrobat file, 100 pages


  1. Randy The Hockey Hacker 08.17.2011

    Had MD-Basic and Beagle Compiler come out a little sooner, the world might have been a different place…

  2. Randy The Hockey Hacker 08.17.2011

    Picture a Beagle super product: my Rose16 editor saving files to your MD-Basic which passes the results to Alan’s Beagle Compiler. It would have been a great integrated system for writing code! Although you’d have probably stuck with the slower microEmacs for your editor. 🙂

  3. Morgan Davis 08.17.2011

    You’re about 20 years late, Randy. But great idea! It’s too bad what happened at Beagle that caused us all to scatter and do our own thing.

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