Last night was my first time in roughly 15 years, that I stayed up past 3am hacking Apple IIGS assembly code.
I ended up writing most of it in TextMate on the Mac, then exporting it, first by filtering it through tr '\n' '\r' to convert it to the kind of line-breaks that the GS/Merlin likes. Then I used the Perl CPAN ProDOS module to export these files to a fresh ProDOS volume image, which was mounted on KEGS and built with Merlin. It is a few steps, but mostly able to be automated, and easy to master when you get the hang of it. Oh, and if you do this, do not use control-I tabs for spacing, Merlin hates that. Be thankful it will import text files without the high bit set on ASCII characters. You'll have to strip that high-bit back off if you do some debugging/etc and bring the files back into UNIX.
There are ways to optimize this kind of development for sure. For example, I'm sure I could set up netatalk somewhere, do all the editing with Merlin on files that reside on the netatalk share, and use svn on the computer hosting the share. Or perhaps I could pull the files off the GS with Silver Platter and an Uthernet card, and then manage them. Regardless, I still insist on source code management.
Anyhow, as I'd hoped, I'm a lot better at this stuff than I was 15 years ago. I made liberal use of macros, tools, and even a relocatable linker segment, to produce a silly program that loads/starts up all the tools and builds a menu bar. Soon I hope to open an svn repository and start making this code available.
One last note, I know I said I'd use MPW on a Powermac and target the IIGS that way, but all it took was a few minutes of trying MPW (and especially, trying MPW on the PowerMac when accessed via VNC), to dissuade me. The Powermac's reprieve is probably near an end, then. Dumpster Ahoy! I'm probably going to be using IIGS native assemblers, compilers, and linkers (the speed penalty won't be so bad after all because I have a TransWarp GS now).
All my goodies have been shipped. Maybe some of them will arrive today. Details comin. I have to get out of the club house now and go back to the Real World. These Real World people have no sense of humor and they want me to do this "work" stuff.
-Chris