User`s guide

Figure 1-3. Banked Memory with Bank 1 in Context
From a transient programs perspective, Bank 1 is always in context. The operating
system can switch to Bank 0 or other banks when performing operating system
functions without affecting.the execution of the transient program. Any bank-switch-
ing performed by the operating system is completely transparent to the calling pro-
gram. Because the major portion of the operating system resides in Bank 0 in banked
systems, more memory space is available for transient programs in banked CP/M 3
systems than in nonbanked systems.
The operating system uses the clear areas in Figures 1-2 and 1-3 for disk record
buffers and directory hash tables. The clear area in the common region above the
operating system represents space that can be allocated for data buffers by GENCPM.
Again, the minimum size of this area is determined by the specific hardware require-
ments of the host microcomputer system.
1-4
1.1 Baked/Nonbanked Organization CP/M 3 Programmer's Guide