Cp/M System Files; Cp/M + .Sys; Ccp.com; Other .Com Files - Commodore 128D User Manual

CP/M System
Files
CPM +. SYS
CCRCOM
Other
. COM Files
The following information is important for technically oriented users
who may want to create their own programs in CP/M mode.
CPM +. SYS is the main CP/M 3.0 system file. It contains all parts of
the system that remain permanently resident in memory: the Basic
Input/Output System (BIOS), which loads into the top of memory; the
Basic Disk Operating System (BDOS), which loads into memory
immediately below the BIOS; and the System Parameters, which
load into the bottom page of memory.
On booting CP/M the Console Command Processor (CCP) is loaded
into memory immediately below the BDOS. The remaining memory,
below CCP and above page 0, known as the Transient Program Area
(TPA) is the area into which applications are loaded. CP/M 3.0 on the
C128hasaTPAof59K.
CCP processes any input in response to the system prompt (A»). It
contains the built-in commands listed in Table 14-1, and also supports
the 14 console editing commands listed in Table 13-1.
Any word entered in response to the system prompt which is not one
of the built-in commands is treated by CCP as a transient command.
When a transient command is encountered, CCP attempts to find
and execute a file whose name is the command word plus the .COM
extension. If CCP does not find such a file on the currently logged
disk, the command word is displayed, followed by a question mark.
CCP then redisplays the system prompt. If more than one word is
entered in response to the system prompt, all words after the first
are treated as parameters to be passed to the transient command.
A language or applications program is loaded and run by invoking it
as if it were a command. All CP/M programs include a .COM file. As
shown in the following pages, the CPM +. SYS and CCP. COM files
are contained on the CP/M system disk.
The other. COM files are transient commands (see Table 14-2). The
file HELP. COM displays messages about the C128 CP/M system and
its commands. If you are not familiar with CP/M and have no other
manuals or books about it, you can print out any HELP you look at.
Press CONTROL and P to send any screen output to the printer;
press CONTROL P again to turn off this facility. If you are printing and
do not want pauses after each screen is printed, enter HELP C128
CP/M [NOPAGE] and follow the directions given on the screen.
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198 USING CP/M MODE—Files, Disks and Disk Drives in CP/M 3.0