Memory Map

In both the low- and high-resolution models, the operating system ROM is in the first 8K of memory space. Cartridge ROM resides in memory between 8K to 16K. Standard screen RAM begins at 16K and occupies 4K bytes. Magic screen RAM begins at location 0. It is the same size as standard screen RAM. Memory space 20K–32K is available for expansion.

When data is read from a memory location between 0–16K, the data come from ROM. When data is written in a memory location (X) between 0–16K, the system actually writes a modified form of the data in location X+16K. The modification is performed by the magic system in the Data Chip and Address Chip. Thus the RAM from 0 to 16K is called Magic Memory.

[NM:82–3]