CONCAT
                           Version 1.0
                          New Features

                         April 24, 1990
                          Gene Pizzetta


DISK SPACE CHECKING:  Before any files are opened, CONCAT checks 
the amount of free space on the target disk and then checks the 
sizes of the source files to determine if there is room to 
complete the concatenation or append.  If there is not sufficient 
disk space, an error message is printed and the operation is 
cancelled.

File sizes are measured in records, which are converted to 
kilobytes after all the input files' sizes are added together.  
Also, another record is added to the total file size calculation 
if the D option is chosen, even though that option could add only 
a maximum of 60 bytes to the resulting output file.  In addition, 
disk space is determined in kilobytes, based on the disk's 
allocation block size.  Because of these limitations, it is 
possible for CONCAT to be fooled into thinking that there is not 
enough disk space for the concatenation (or, especially, append) 
even though adequate free space exists.  Moreover, space checking 
adds a second or more to CONCAT's running time, depending on the 
number of source files involved and on whether the various source 
drives are already logged in.

For the above reasons, a new option allows bypassing disk space 
checking for those impatient souls with more guts than brains (-:

     S    Toggle disk space checking.

A configuration byte at 119h determines whether CONCAT will check 
disk space by default before doing anything.  A non-zero value 
turns this feature off.  The S option will then toggle space 
checking back on.

ERRORS:  In addition to setting the program error flag, an error 
also causes CONCAT to invoke the error handler, if one is 
running.  The ZCPR3 error flag is set as follows:
      8   ambiguous or missing output or source filename
     10   source or target file not found or not given
     11   disk or directory full (write error)
      4   all other errors
These same codes are passed to the error handler.

ABORTING:  Normally the console is checked for a character 
everytime a sector of an input file is read.  If the character is 
a ^C, then CONCAT cancels the operation, just as if an error 
occurred, erasing the incomplete output file.

If CONCAT is operating in Append mode, however, entering a ^C has 
no effect.  A file that is being appended to is irrevocably 
changed as soon as a single byte is appended to it.  Rather than 
leave such a file in an unknown condition, CONCAT ignores any 
^C's and continues appending until the job is finished.

HELP SCREEN:  The actual name by which CONCAT was invoked is now 
displayed by the usage message.  Also, the current state of the 
two toggle options (Q and S) is displayed.