OS-9 Assembly Code Development
From F256 Foenix
Overview
Each process in NitrOS9 is allocated its own 64K address space. When run, the program object code is loaded into one memory space, and the variables and data structures are loaded into the other.
Registers U, Y, DP and SP are set with U = start of data area, Y = end of data area, DP = page # of beginning page, SP = end of data area + 1