I've just been catching up on years of the Propeller forums!
I recently repaired a TRS-80 clone and have been looking at ways to exploit the expansion interface, and connecting up a Propeller is definitely a good option. I have played before using SpinStudio.
One idea I have is to improve the video (e.g. adding colour and new characters) by using the 80 Column Color 8x8 NTSC Text Driver, but I need it to be 16 rows of 64 columns, and instead of 8x8 characters I need 8x12.
The trouble is I am not very familiar with video generation. I've been reading the docs and the code of various drivers available on the parallax object exchange, and this driver looks the best for my needs seeing it already supports 64 characters per row, and 16 lines of height 12 pixels matches 24 lines of height 8 pixels.
The thing that is particularly puzzling me is how scanlines are mapped to rows inside the Text_GR.spin code.
I am hoping that all that will be needed is an appropriate font definition and some minor changes to the pixel fetching loop, and would appreciate any pointers.