FILE MANAGER
SECTION 3.3
FILE STRUCTURE AND MEMORY ORGANISATION
3, 3, 1
3,3,2
3,3,3
HUNTER is capable of storing a great deal of differing infor-
mation within its large memory. There may be Basic programs,
text files, data files or object code CP/M programs,
Superficially the operating system handles its memory in a
similar manner to disk backing stores, and indeed may be
considered as a 'RAM Disk', However HUNTER is much faster than
any disk system and incorporates special facilities to enable
the memory to be efficiently utilised,
HUNTER's File Manager DEMOS (Disk EMulation Operating System)
manipulates files and runs CP/M programs. The File Manager
environment is totally unconnected with Basic,
ENVIRONMENT MID
STRUCTIIRE
The File Manager facility is located in firmware, so there is no
overwriting of existing programs in execution RAM, A CP/M call
O, or a JMP 0000 both cause a "warm" start which executes the
File Manager in ROM. This would be a typical method of ending a
,COM program, Entering the File Manager on power up is
equivalent to a "cold" start, in which the operating system is
completely reset, although programs in RO are preserved,
HUNTER's File Manager will implement several commands and load
and execute ,COM files, Files may be erased, renamed or saved
from memory, ASCII files may be displayed on the screen, as can
the file directory, Finally, there is a facility for loading and
dumping the files via the serial port in either Intel hex format
or 8 bit binary format,
The File Manager is structured around the CP/M compatible
operating system and file structure. The RAM filespace,
organised in exactly the same manner as disk based files, can
be accessed through the system calls, Utility commands can be
quickly selected from the soft keys,
FILE SPACE
Files are stored, as on magnetic disk, in records of 128 bytes,
grouped by 16
1
s into 2K bytes, This means that the smallest
file size is 2K bytes, but, as with magnetic media, allows for
very large files to be stored.
The memory space is allocated by the file manager and is
transparent to the user,
VER.V09F
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