[Coco] Coco BASIC files

[arikboke at yahoo.com]

Folks,

Some please explain to me why BASIC comes in 'BASIC binary" and 'BASIC ascii'. 
Are not BASIC sources supposed to be .TXT files?  Also, when placed onto
virtual diskettes via IMGTOOL in MESS, often times I am unable to access said
files (neither ASCII nor binary).  I keep getting "FM? ERROR ..." or some
variants.  Have they become corrupt?

Sincerely,
David