


                        OS-9 SOURCE FILE INFORMATION


      Description of the source

       1 - The "Kernal" is composed of two parts.  OS9P1 is the  source  
      for the "P1" ROM which goes at $F800.  OS9P2 contains the rest of 
      the  OS-9 Kernal and the INIT module.  The OS9P2 and INIT modules
      go in the  "P2" ROM along  with the BOOT module.   You will  find
      source  to a BOOT module for either the specified disk controller
      or a representative sample.


       2 - There are three device  drivers  included.   "Acia"  is  the  
      MC6850  acia  device  driver.  "Pia" is the MC6821(20) pia device 
      driver.  The Acia and Pia drivers are "SCF" (sequential character 
      file)  type device drivers.   Then there is a DRVR  (disk driver)
      for either the specified  controller or a representative  sample.
      The disk  driver  is an "RBF" (random  block  file ) type  device
      driver.


       3 - There are several device descriptors included.  "Term", "T1"
      and "P1"  are acia type device descriptors. The first two are for
      terminals and  the other is for a serial  printer.   "P" is a pia
      type device  descriptor for a parallel printer.


       4 - The "Shell" is source for the  "command  interpreter".   Our  
      experience  has  shown  that  changes  to  shell  can often cause 
      seemingly  unrelated  problems  which  are really shell problems.
      Therefore be careful if you modify this source.


       5  -  The "Sysdefs.sys" file is  used to define  the  particular
      system for which this source was created.   It should be moved to
      your DEFS  directory.   It is used by many of the source files to
      define changeable configurations for different systems. It is the
      user's  responsibility to check  that the  sysdefs match  what is
      currently  needed for his  system and make any  required changes.
      The  defsfile is a convenient file for "using" all the  different
      OS-9 definitions files.


       6  -  In  addition  there  is an assortment of example utilities 
      which will give you a good look at how to use  OS-9  in  assembly  
      language  programs.  Comments on several of these: You may notice
      a similarity  between Copy, List, and Merge.  This is a result of
      OS-9's  unified I/O  handling.   Note  that  SYSGO is the  system
      starter  module which sets  up the default  directories and keeps
      the system  going even if shell "dies".   Details on SYSGO can be
      found in the System Programmers Manual.


       7  -  NOTE:  Not all of the utilities are included in the source
      package.  The intent in sending out any of them is to guide users
      into good programming techniques.   Those sent are representative
      of the utilities done by Microware.


          (C) 1980 Microware Systems Corporation and Motorola Inc.
