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--- tutorials:fortran [2014/01/11 02:21]
papa [Input/Output Devices]
+++ tutorials:fortran [2022/03/19 09:52] (current)
papa [CPU/Elapsed time report on program termination]
@@ Line 9: / Line 9: @@
 ===== Peculiarities =====
+==== CPU/Elapsed time report on program termination ====
+The FORTRAN compiler adds a report on CPU and elapsed time used by the program that prints at the end of every program run, like:
+  CPU time 0.08 Elapsed time 0.09
+This message can be suppressed by adding the following line to your program source:
+        CALL QUIETX
+==== DATE subroutine bug ====
+Although the TOPS-20 operating system as a whole survived the Y2K crisis, the FORTRAN DATE subroutine did not fare as well.
+DATE is supposed to return a ten-character string representing the current system date with the format:
+''dd-mmm-yyb''
+Where:
+| ''dd'' | Day of month (leading zero converted to blank) |
+| ''mmm'' | Three-character abbreviation of month ("Jan", "Feb", ...) |
+| ''yy'' | Last two digits of year |
+| ''b'' | blank character |
+However, since the year 2000, the DATE has set the ''yyb'' portion of the returned date to the //first three// digits of the current year, giving the same value for all years of a given decade. For example, for every year between 2010 and 2019, DATE returned "201" in the ''yyb'' portion of the date string.
+This renders the year portion of DATE's output useless for most purposes. A work-around is to program a date subroutine in another language that correctly processes the TOPS-20 system date (such as MACRO assembly language) and call that subroutine from your FORTRAN program instead of the FORTRAN DATE subroutine.
 ==== Input/Output Devices ====
@@ Line 28: / Line 56: @@
 Below is a list of FORTRAN-20 logical unit assignments. For file input or output, you may use any of the units assigned to disk (0, 1, 20-24, 30-99). If you do not specify a file name when you open the logical unit, FORTRAN-20 will use the default file name (in your currently connected directory) corresponding to the unit you are opening as shown in the table.
-^  Unit  ^Device^Default filename^Usage^
+^  Unit  ^Device^Default filename^Usage^  Available  ^
-|  0  |DSK|FOR00.DAT|Disk|
+|  0  |DSK|FOR00.DAT|Disk|  YES  |
-|  1  |DSK|FOR01.DAT|Disk|
+|  1  |DSK|FOR01.DAT|Disk|  YES  |
-|  2  |CDR|FOR02.DAT|Card reader|
+|  2  |CDR|FOR02.DAT|Card reader|  NO  |
-|  3  |LPT|FOR03.DAT|Line printer|
+|  3  |LPT|FOR03.DAT|Line printer|  NO  |
-|  4  |CTY|FOR04.DAT|Console teletype|
+|  4  |CTY|FOR04.DAT|Console teletype|  NO  |
-|  5  |TTY|FOR05.DAT|User teletype|
+|  5  |TTY|FOR05.DAT|User teletype|  YES  |
-|  6  |PTR|FOR06.DAT|Paper tape reader|
+|  6  |PTR|FOR06.DAT|Paper tape reader|  NO  |
-|  7  |PTP|FOR07.DAT|Paper tape punch|
+|  7  |PTP|FOR07.DAT|Paper tape punch|  NO  |
-|  8  |DIS|FOR08.DAT|Display|
+|  8  |DIS|FOR08.DAT|Display|  NO  |
-|  9  |DTA1|FOR09.DAT|DECtape|
+|  9  |DTA1|FOR09.DAT|DECtape|  NO  |
-|  10-15  |DTA2-7|FOR10 - 15.DAT|  "  |
+|  10-15  |DTA2-7|FOR10 - 15.DAT|  "  |  NO  |
-|  16-18  |MTA0-2|FOR16 - 18.DAT|Magnetic tape|
+|  16-18  |MTA0-2|FOR16 - 18.DAT|Magnetic tape|  NO  |
-|  19  |FORTR|FOR19.DAT|Assignable device|
+|  19  |FORTR|FOR19.DAT|Assignable device|  NO  |
-|  20-24  |DSK|FOR20 - 24.DAT|Disk|
+|  20-24  |DSK|FOR20 - 24.DAT|Disk|  YES  |
-|  25-29  |DEV1-5|FOR25 - 29.DAT|Assignable devices|
+|  25-29  |DEV1-5|FOR25 - 29.DAT|Assignable devices|  NO  |
-|  30-99  |DSK|FOR30 - 99.DAT|Disk|
+|  30-99  |DSK|FOR30 - 99.DAT|Disk|  YES  |
 ===== Extensions and additions =====

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