[Coco] OS9 Process space questions

[Paul Fitch]

Heres my question.  When running any program, OS9 assigns the program a
maximum of 64k to run in.  Is it always 64k, or assigned in 8k chunks?  Is
it dynamic? 
 
 ie, a program is started with X memory, or the minimum memory it will fit
in (not sure which).  After startup, the program determines that additional
memory is required.  
 
Are more blocks allocated on the fly, or is the memory request made only at
startup, ala Copy #24k?