Compiling Digital Research CP/M 2.1
===================================

  The supplied source is (I hope) all that is necessary to build the CP/M 2.1
binary distribution under Unix.

  The Makefile has been written for GNU Make. You will need:

* The PL/M development system from the Unofficial CP/M Website
	<http://www.cpm.z80.de/binary.html>

* The zxcc emulator (version 0.3 or later) installed 
	<http://www.seasip.info/Unix/Zxcc/>
* The thames emulator (version 0.1.0 or later) installed
	<http://www.seasip.info/Unix/Thames/>

  The PL/M system contains the PLM80 compiler, the ASM80 assembler, and the 
ISIS emulator. Unpack these to separate directories.
  
  In order to generate binaries identical with the Digital Research 
originals, you will then need to downgrade the PL/M compiler from version 
4.0 to version 3.1, which can be found at 
    <https://github.com/ogdenpm/intel80tools/tree/master/itools/plm80>

  Edit the shell script run_thames to set the four directories:

ISIS_F0  source code directory
ISIS_F1  PLM80 compiler
ISIS_F2  ASM80 assembler
ISIS_F3  ISIS emulator and libraries

  'make all' will then set the build in motion. Since the build tools do not
return error codes, you will have to watch for error messages yourself,
and stop the build if you see one.

  Unlike my similar release of CP/M 3, I have made no attempt to fix bugs or
add features, and there is no include file containing a build date.
