Owner`s manual

Page 1-2 Chapter 1
A "command file" is a text file that contains system commands. When you call the
command file, the monitor reads and obeys the instructions contained in the file.
Each time the system is powered up or reset, the Alpha Micro hardware causes the
monitor program—which has the system name and a .MON extension—for example,
AMOSL.MON), to be loaded into memory and executed. The monitor reserves a small
memory partition at the far end of memory for processing the system initialization
command file. Then, the monitor loads the system initialization command file into that
area of memory and starts processing it.
Some of the lines in the system initialization command file represent one system
function or parameter which determines the characteristics of the monitor. Others set
up various aspects of your computer. The monitor checks the system initialization
command file to find out what devices are on the computer and what special programs
and functions you want to add to the your system memory. As the monitor reads in a
line from the system initialization file, it loads in the specified program from DSK0:[1,4]
and runs it.
The first thing the system initialization command file does is define one or more jobs;
next, it defines one or more terminals. The monitor automatically attaches the first job
defined (called the "Operator Job") and the first terminal defined (called the "Operator
Terminal"), and then proceeds to process the rest of the system initialization command
file under the control of that job in the temporary memory partition previously allocated.
The monitor executes each command line as it would a command in any other
command file. However, because this command file is the system initialization
command file, the monitor performs some of the commands differently than it would the
same commands after the computer is up and running. The execution of certain
commands (such as JOBS, TRMDEF, DEVTBL, etc.) performs the actual system
generation.
The command that finishes the system initialization is "MEMORY 0"; this tells the
monitor to free the temporary memory partition the system initialization command file
was processed under and give the Operator Job all available memory not already
assigned to other jobs.
Once the monitor has finished processing the system initialization command file, your
computer is up and running. We call this entire process, from the time you turn on your
computer or push the reset button until Ct is up and running, "bootup."
You can think of the AMOS monitor file as being a skeleton monitor—in the process of
executing the system initialization command file, the monitor adds to itself in memory by
filling in various tables in memory with information on terminals, disks drives, and other
devices attached to the computer. Only by processing the information in the system
initialization command file can the monitor find out the exact configuration of your
hardware, and what jobs you want to run on your computer.
System Operator’s Guide to the System Initialization Command File, Rev. 03