Recently, I’ve been working on a little demo for the Apple II and I finally got around to wiring up some tools to be able to write my code in vim and then compile and run my code side-by-side in xkegs using Merlin 16+. I put together a vim (vi) syntax highlight file that has (I think) all of the 65c02 and 65816 opcodes plus some Merlin directives. It’s probably not complete, but I find it works well and is extremely useful for me.
Click here to download the latest version of the syntax highlighting file, along with a README that describes how to install it.
Ultimately, I really like the Merlin editor. It’s super efficient for its time and Glen Bredon was a real UI genius when it came to productive environments. But even mighty Merlin has the un-fixable limitation of an 80×24 character limit. Obviously, our modern computer displays are capable of much more text on a screen. Now with the ability to use vim to edit code, I have found it incredibly helpful when writing longer passages of code with a large window.
Assembly language is very verbose but with short commands. So programs are written in an extremely vertical format. Having the ability to edit on a modern machine helps a lot, as the highest density text mode for the Apple II is 80×24 characters. The 80-column width is sufficient, but only having 24 rows of code visible can make understanding and debugging complex routines difficult.