5  IF  ERROR  THEN 260
10  DIM A$[100]
20  B=BRK(0)
30  PRINT LIN(1);"INSTRUCTIONS? ";
40  LINPUT A$
50  A$=UOS$(A$)
60  IF A$[1,1]#"Y" THEN 250
70  PRINT LIN(1);"YOU ARE ON THE SYSTEM PUBLIC LIBRARY, L101. THIS IS"
80  PRINT "THE CONTROLLER PROGRAM YOU ARE IN NOW. THE CONTROLLER LETS"
90  PRINT "YOU GET INFORMATION ON OR USE ANY OF THE PROGRAMS IN THE"
100  PRINT "SYSTEM PUBLIC LIBRARY."
110  PRINT LIN(1);"THERE ARE FIVE COMMANDS YOU MAY ENTER:"
120  PRINT "1) PRINT ALL PROGRAMS, AND THEIR SUBJECT, WITH A SHORT"
130  PRINT "   DESCRIPTION OF WHAT THEY DO."
140  PRINT "2) PRINT ALL THE PROGRAMS ON ANY ONE SUBJECT, WITH A SHORT"
150  PRINT "   DESCRIPTION OF WHAT THEY DO."
160  PRINT "3) PRINT THE SUBJECT AND A SHORT DESCRIPTION OF ANY PROGRAM."
170  PRINT "4) LIST OF AVAILIBLE SUBJECTS (FOR COMMAND 2)."
180  PRINT "5) EXECUTE A PROGRAM. YOU TYPE THE NAME OF THE PROGRAM"
190  PRINT "   YOU WANT, AND IT WILL START. WHEN IT IS DONE YOU WILL BE RETURNED"
200  PRINT "   TO THE CONTROLLER."
210  PRINT LIN(1);"IF YOU DON'T KNOW WHAT TO TYPE IN RESPONSE TO ANY PROMPT"
220  PRINT "FROM THE CONTROLLER, TYPE '//HELP' AND YOU WILL BE TOLD WHAT"
230  PRINT "THE CONTROLLER WANTS. TO LOG OFF OF THE SYSTEM PUBLIC ACCOUNT,"
240  PRINT "TYPE '//STOP' TO ANY CONTROLLER PROMPT."
250  CHAIN X,"*HELP"
260  SYSTEM X,"BYE"
270  END 
