1) 20-OCT-78 **STRING I/O**
It is now possible to define strings to be the source and destination
of stream i/o. This allows the use of parsing algorithms developed
for i/o to be applied to strings. There are two new routines
%EXTERNALROUTINE SDEF INPUT(%INTEGER N,%STRING(1)%NAME STRING)
%EXTERNALROUTINE SDEF OUTPUT(%INTEGER N,%STRING(1)%NAME STRING)
where N is the stream number in the range 1-15. and STRING is the string
to be read or written.  These are equivalent to DEFINE INPUT and DEFINE
OUTPUT and use the same stream system. Thus the other routines operate
as before i.e. SELECT INPUT/OUTPUT, CLOSE INPUT/OUTPUT and
RESET INPUT/OUTPUT. An End-of-file condition occurs on input when the
end of a string is reached, and on output the stream needs
to be closed before the string length is added to the string.

2) 23-Oct-78 **FILESPEC records**
The length or the string item 'SWITCHES' in the 'FILESPEC' record
definition in PERMS.IMP has been increased from 20 to 39.
programs using FILESPEC records explicitly will need to be
recompiled before being re-linked.

3) 20-DEC-78 **LIB: SEARCHING**
DEFINE INPUT and XDEFINE INPUT will now look for a file on a users
library area if the file is not found in the users directory area.

4) 20-DEC-78 **I/O ERRORS**
The message "I/O transmission error" SIGNAL 4,1,status
has been replaced by:-
"Input error status #nnnnnn" SIGNAL 4,1,stream/chan
"Output error status #nnnnnn" SIGNAL 4,2,stream/chan
 where the status bits nnnnnn(in octal) are defined in the DECsystem-10
Monitor Calls Manual for the appropriate device.

5)  31-Jan-79 **PERMS.IMP**
PERMS.IMP reduced by the removal of the definition of JOBDAT array
and by using calls to DEFINPUT, DEFOUTPUT, XDEFINPUT, XDEFOUTPUT,
SELINPUT and SELOUTPUT such that the parameters are passed direct
without intermediate storage.

6) 31-Jan-79 **Unassigned streams**
The unassigned state of streams changed to cause an event when accessed
instead of being assigned to the NUL: device. Thus input from an
unassigned channel gives
   %SIGNAL %EVENT 8,1,stream  "Input from unassigned stream"
   and output gives
   %SIGNAL %EVENT 8,2,stream  "Output to unassigned stream"

7) 15-Feb-79 **Non-blocking i/o**
   If you set up streams to operate with non-blocking i/o you will get the
   following two events when an IN or OUT UUO returns without blocking
   %SIGNAL %EVENT 9,1,stream "No input on stream"
   %SIGNAL %EVENT 9,2,stream "No output to stream"

8) 25-Feb-79 **REENTER trapping**
   When a program is reentered by the monitor command REENTER after
   say a control C interruption, the %signal 0,-2,0 "Program REENTERed"
   is fired off and this can be trapped.

9) 23-Mar-79 **SWITCH ARG library routine**
   It should be noted that the second argument is a %STRING(11) and not
   (15) as in the original documentation and that the switch
   string passed as a parameter has been modified so that if a matching
   switch is found, the switch is removed from that string. Thus
   a series of switches can be searched for until the string="".