You sound like you know a bit about TI-99s, so let me ask you this: Do you have any idea why they made the lower case character set be small upper case letters instead of real lowercase like the Apple II or C64? A couple of years ago I did a Sunday morning project of inserting the Apple II font into the TI-99 ROM to run on an emulator, and other than having to shift the j's and g's up a pixel or two it worked beautifully.