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  |         ================================================     |
  |	    |						   |	 |	
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  |         |       *****  Digital Research C  *****       |     |
  |         |                                              |     |
  |	    |	         for the CP/M-86 Family	           |	 |
  |         |             of Operating Systems		   |	 |
  |         |                                              |     |
  |         |                ---------------               |     |
  |         |                                              |     |
  |         |               READ.ME File Notes             |     |
  |         |                                              |     |
  |         |               - November 1983 -              |     |
  |         |                                              |     |
  |         |             Digital Research Inc.            |     |
  |         |                 P.O. Box 579                 |     |
  |         |           Pacific Grove, CA  93950           |     |
  |         |                                              |     |
  |         ================================================     |
  |								 |
  |								 |
  |								 |
  |       This file presents enhancements  and  modifications    |
  |       made to Digital Research  C  Language  software and    |
  |       documentation.   Changes  described  in  this  file    |
  |       apply  to   Digital  Research C  compiler  software	 |
  |       Version 1.1  and the "C Language Programmer's Guide	 |
  |	  for  the  CP/M-86  Family  of   Operating  Systems"	 |
  |	  Second Edition:  October 1983.			 |
  |								 |
  |       You can print  the information in this file on your    |
  |       line  printer  using  8 by 11 inch  paper  with the    |
  |       printer set to 6 lines per inch.   You can trim the    |
  |       pages along the dotted  lines and place  the  pages    |
  |       in your product documentation binder.                  |
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  |  Digital Research C READ.ME File Notes          October 1983 |
  |                                                              |
  |                                                              |
  |      1. The  following  rule   applies  to  any  assembly    |
  |         language  routine  designed to  interface  with a    |
  |         small model C program.                               |
  |	                                                         |
  |	  o If the assembly program  alters  values in the ES    |
  |	    register,  you must save the original value in ES    |
  |         upon entry to the routine.   You must restore the    |
  |	    original ES value upon exit from the routine.  If    |
  |	    you call a C function from  the assembly routine,    |
  |	    you must restore the original ES before the call.    |
  |								 |
  |	 2. The C compiler now  has  two  additional  command  	 |
  |	    line options.					 |
  |	    							 |
  |       o Use the -E option to change the maximum number of	 |
  |	    errors the compiler detects before  stopping  the	 |
  |	    compilation.        The  default  is  10  errors.	 |
  |	    The following example changes the  maximum number	 |
  |	    of errors to 25.					 |
  |								 |
  |	    B>DRC PROGRAM -E25					 |
  |	                                                         |
  |	  o Use the -S option  to  reduce  the  size  of  the	 |
  |	    symbol table by truncating  symbolic names during	 |
  |	    compilation.  Specify a  length  after  the -S as	 |
  |	    shown in the following example.  In this example,	 |
  |	    all symbolic names are truncated to 8 characters.	 |
  |								 |
  |	    B>DRC PROGRAM -S8					 |
  |								 |
  |	 3. Symbolic names  are now significant up  to  forty    |
  |	    (40) characters instead of eight (8).  Use the -S	 |
  |	    option to  reduce  the  symbol  table  size  when	 |
  |	    compiling large programs that use lengthy  names.	 |
  |	                                                         |
  |	 4. The compiler displays  a  warning message if your	 |
  |	    program attempts to compute the address (&)  of a	 |
  |	    register variable.				 	 |
  |	                                                         |
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  | Digital Research C READ.ME File Notes	    October 1983 |
  |								 |
  |								 |
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  |	 5. You can specify a user number in  addition  to  a	 |
  |	    drive specification in a reference to a filename.	 |
  |	    filename as shown in the following example.		 |
  |	                                                         |
  |	    f=open("3A:foobar.c",read);				 |
  |								 |
  |	 6. You can create overlays  that  either  accumulate	 |
  |	    or overlay the data in various overlays.  Use the	 |
  |	    LINK86 CUM  option  to  specify cumulative  data.	 |
  |	    Use  the   LINK86   NOCUM   option   to   specify	 |
  |	    non-cumulative data.  Overlays on the same  level	 |
  |	    share data areas.					 |
  |								 |
  |	 7. The  C  compiler  has  three  additional  library	 |
  |	    functions: readl, writel, and rename.		 |
  |								 |
  |	  o The readl function is just like the read function	 |
  |	    except readl uses a long int argument and returns	 |
  |	    a long int value.					 |
  |								 |
  |	  o The  writel  function  is  just  like  the  write	 |
  |	    function except that it uses a long int  argument	 |
  |	    and returns a long int value.			 |
  |								 |
  |	  o The rename function  uses two  string  arguments.	 |
  |								 |
  |	    rename(file1, file2)				 |
  |								 |
  |	    The first argument (file1) is the file to rename.	 |
  |	    The second argument (file2) is the new file name.	 |
  |								 |
  |	 8. If you mix a C  program  with  assembly  language	 |
  |	    routines, your main program must be a  C function	 |
  |	    to  initialize  the  C  environment.   This  only	 |
  |	    requires a few extra bytes of space as  shown  in	 |
  |	    the following example.				 |
  |								 |
  |	    main(){maina86();}					 |
  |								 |
  |      9. The -X option  has been disabled because the size	 |
  |	    of  the  inline  code  that  saves  and  restores	 |
  |	    registers in an assembly routine call is smaller.	 |
  |								 |
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  | Digital Research C READ.ME File Notes	    October 1983 |
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  |	10. The  -c and -m  options  for  compact  and medium	 |
  |	    model compilation are no longer supported.		 |
  |								 |
  |	11. The compiler  treats  pointers  in  a  big  model	 |
  |	    program  as  long integers.    This  can  produce	 |
  |	    incorrect results if not used with caution.		 |
  |								 |
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  |                       END of READ.ME FILE			 |
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