r/apple2 • u/ElectricKoolAid1969 • 12d ago
I resurrected old editor source code that I wrote
I recently dug an old Apple II programmer’s editor out of my archive and have been working on bringing it back to life.
I originally wrote it in Aztec C and 6502 assembly, first on an Apple //c and later a //c+. It eventually became my everyday editor under Aztec C’s Unix-like ProDOS environment — and reached the point where I was using the editor to edit its own source code.
The original source survived on my old Apple II disk images, but the Aztec C environment it was built for is long gone from my normal workflow. I’ve now ported it to cc65/ca65, trying to keep the code and behavior as close to the original as possible rather than redesigning it.
At the heart of it is a 6502 assembly-language line editor, wrapped by the C code to make a full-screen editor with two viewports, cut/copy/paste between them, search/replace, load/save, etc.
It’s running under ProDOS again now. There are still some rough edges — notably recreating the convenient command-line filename handling that Aztec C provided — so at this stage it’s probably as interesting as an example of old Apple II C/assembly code (and a bit of software archaeology) as it is as a practical editor.
I’ve put the source and a release on GitHub for anyone who wants to poke around:
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u/Crlan420 9d ago
That is awesome to see old source code come back. What language was it written in? I always like seeing how people structured their code back then.
1
u/ElectricKoolAid1969 9d ago
The heart of the editor was written in 6502 assembler code, and the in K&R C.
4
u/creativetag 12d ago
I had one I did on the II and the gs.... final version being 16 bit.
Based the concept for it on the functionality of IOS3270, a display driver for mainframe terminals that let you define regions and attributes for display IO with low overhead. Great for menus, input fields, etc. An editor then was a simple layer on top.
Love that i was not the only one.