E_ R_ R_ O_ R_   C_ O_ D_ E_ S_   F_ O_ R_   U_ /_ W_ - F_ O_ C_ A_ L_

            V_ E_ R_ S_ I_ O_ N_  4_ / E_  -  O_ C_ T_ O_ B_ E_ R_  1_ 9_ 7_ 8_


                         CTRL/C returns to OS/8
                     CTRL/F/P interrupts the program
                 CTRL/S suspends output to the terminal
              CTRL/Q restarts terminal output (8/A,e only)

?        . . . . . . Keyboard interrupt or restart from location 10200
?0/1.0/3*  . . . . . . . . . . . . . . . . .Secondary input file missing
?0/1.11*  . . . . . . . . . . . . . . No secondary input file to resume
?0/1.50/   . . . . . . . . . . . . . . . . .Group number greater than 31
?0/1.93   . . . . .Non-existent line number in a MODIFY or MOVE command
?0/3.10/   . . . .Line called by GO, IF, J, R, Q, L B, or L R is missing
?0/3.30/   . . . . . . . . . . . . . . . . . . . . . . . Illegal command
?0/3.47   . . . Line or group missing in DO, ON, JUMP, L GOSUB or a FSF

?0/4.35   . . . . . . .Bad syntax in a FOR command (missing semicolon?)
?0/6.0/3   . . Illegal use of a function or number: ASK, YNCREMENT, ZERO
?0/6.41   . . . . . . . . . .Too many variables (ZERO unnecessary ones)
?0/7.44   . . . . . . .Operator missing or illegal use of an equal sign
?0/7.67   . . . Variable name begins with 'F' or improper function call
?0/7.76   . . . . . . . . . . . Double operators or an unknown function
?0/8.10/   . . . . . . . . . . . . . . . . . . . Parentheses don't match
?10/.50/   . . . . . . . . . . . . . . . . . . . . . . Program too large

?12.10/   . . . . . . . . . . . .Error detected in the BATCH input file
?12.40/   . . . . Keyboard buffer overflow (eliminated in 8/e versions)
?13.65   . . . . . . . . . . . Insufficient memory for BATCH operation
?14.15   . . . . . . . . . . . . . . . . . . . Display buffer overflow
?14.50/   . . . . . . Bad Sense Switch number on a PDP12 (range is 0/-5)
?14.56   . . . . . . Illegal external sense line (PDP12 range is 0/-11)
?17.22   . . . . . . . . . . . . . . . . . . . . . FRA not initialized
?17.33   . . . . . . . . . . . FRA index too large (exceeds file area)
?17.62   . . . . . . . . . .FRA mode error: only modes 0/,1,2,4 allowed

?18.42   . . . . . . . . . . FCOM index too large: reduce program size
?19.72   . . . . . . . . . . . . . . . . . . . . . . Logarithm of zero
?21.57   . . . . . . . . . . . . . . .Square root of a negative number
?22.65   . . . . . . . . Numeric overflow: too many digits in a string
?23.18   . . . . . . . .OUTPUT ABORT or CLOSE requested too much space
?23.37   . . . Output file overflow: recover with: O O name;O A FLEN()
?23.82*  . . . Cannot open output file (file open, too big or no name)
?24.0/5*  . . . . . . . . . . . . . . . . . . .No output file to resume

?24.25   . . . . . . . . . . . . . . . . . . . . .Illegal OPEN command
?24.35   . . . . . . . . . . . . . . . . . . . .Illegal RESUME command
?24.40/*  . . . . . . .Input file not found (wrong name? wrong device?)
?24.47   . . . . . . . . . . . . . . . . . . .No input file to restart
?24.52*  . . . . . . . . . . . . . . . . . . . No input file to resume
?25.0/2   . . Stack overflow: reduce nested subroutines and expressions
?25.60/*  . . . . . . . Device does not exist or illegal 2-page handler
?26.0/7   . . . . . . . . . . . . . . . . . . . Illegal LIBRARY command
?26.32   . . . . .File specified is already deleted (wrong extension?)

?26.39   . . . File loaded is not a FOCAL program - better reload UWF!
?26.56   . . . . . . . . .Program requested is missing (wrong device?)
?26.66   . . LIBRARY SAVE error: no name, device full, or no directory
?27.18   . Attempted LIBRARY operation on a device without a directory
?27.75   . . . . . . . . No length specified in a LIBRARY ZERO command
?27.90/   . . . . . . . . . . . . . . . . . . . . . . . . .Zero divisor
?29.25   . . . . . . Cannot use the '<>' construction with OPEN OUTPUT
?29.38   . .Device error (write-lock, bad checksum or illegal request)

      *  Denotes an error from a command with an optional error return
-< or _   Indicates EOF detected in input - I/O continues from terminal

?....?   TRACE feature: Text enclosed by '?' marks (not inside quotes)
         is typed during execution to help find the source of an error
         The value of each expression in a SET command is also printed


?_____   ______________________________________________________  extra

?_____   ______________________________________________________  error

?_____   ______________________________________________________  codes


 To restart after a MONITOR ERROR 2 (output to a write-locked device):
 Write-enable it, type .ST 10/0/(CR), then 'L D DEV:' before continuing.

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 FOCAL and OS/8 are trademarks of Digital Equipment Corp. Maynard MASS