First, Perispomenon sent me an rtf file in both betacode and unicode, and I must say, I'm delighted. It is obviously the result of some dedicated work, and it was very kind to make it available. Thank you!
Second, to Annis, yes, I'm a total Emacs geek. I keep my hand in on vi and find it very useful, but for lots of typing, Emacs is the way to go for me.
Unfortunately, I've NEVER gotten Emacs to display polytonic fonts. Annoying, because almost all my other programs have no problem. Emacs font configuration has always been alien to me. Clearly, I need to study this more; additionally, it seems on my system, the font configuration files DO have to be modified to allow the polytonic deadkeys to work at all. Nevertheless, I've noted down the references you said, babel and Ibycus4, and as soon as I write this, I'm looking into those.
Third, I found several converters, and I'm checking out that vi one too, but just as a fun project, I decided to write my own using Perl and a custom xml notation. I want to be able to type like this: <bc>mh=nin a)/eide qea\ phlhi+a/dew )axilh=os</bc>
And have this come out inline with English text: Î¼á¿†Î½Î¹Î½ á¼„ÎµÎ¹Î´Îµ Î¸Îµá½° Î Î·Î»Î·Î¹Ìˆá½±Î´ÎµÏ‰ á¼ˆÏ‡Î¹Î»á¿†Î¿Ï‚ with the tags stripped out.
Note that I use <bc></bc> for <betacode-begin><betacode-end>, but that's arbtrary on my part. It would be easy enough to use any other tag at all. (That's the beauty of xml.) The idea of using the tags makes the program super efficient in that it will not try to analyze every character, only the ones within the tags. Second, by placing the more common letters and letter forms first in the search order, I get an exponential performance boost. Probably that vi converter, if it's powerful for large files uses a similar algorithm (design logic), but the converters I found, did not; thus are really suited for small files on a personal computer rather than large files on a network.
I'm about halfway done with the converter, a Perl program. I've found that typing in beta code is actually really efficient, maybe even easier than a polytonic keyboard layout, so even when I get the text entry bug sorted, I may still use beta code out for the speed of use!
Fourth, I agree with GGG (You don't mind if I use the abreviation, do you?) That a cheat sheet should be compact. Then it's really useful. At some point (soon), I'll put up my versions for critique/review/correction/suggestion.