UNIVAC 1100 implementation


EDA is called by typing:

@EDA*EDA.EDA

The UNIVAC 1100/61 implementation at Universite de Geneve is a 25 variables by 120 cases implementation.

The STOP/QUIT command has an additional parameter to specify the printer on which the print file is output. Default printer is PRASC, optional printers are SITE (or PR) and DELETE. SITE (or PR) is the on site printer PRASC, DELETE drops the print file (in fact it is a SYM to a dummy device). Print file names on UNIVAC are "time" prefixed by PR$. Other printers may be specified enclosed within " ".

Input files MUST be in ASCII (not FIELDATA), otherwise an I/O error occurs. (Use a processor like ED or DATA for conversion).

If a $ symbol is encountered on column 1, the rest of the line is submitted as control image to the system interface CSF for processing. The leading @ is provided by EDA. Note that the image should be terminated by the sequence blank . blank., e.g.

$asg,t file12. .

The following statements are allowed : ADD ASG BRKPT CAT CKPT FREE LOG MODE QUAL RSTRT START and USE. In terminal mode these statements can be processed in transparent (asynchroneous) control mode, i.e. preceded by @@, but this not possible in macros, e.g. when executing automatically a macro upon loading a WA from an EF. Use only the above control statements, other statements will cause EDA to abort (no checks are performed).

Zero divide and other arithmetic exceptions which might occur during execution are diagnosed by a system message ('DIVIDE FAULT') up to 120 times; if this limit is reached, the program aborts.

On UNIVAC the suffixes to EDA file names are -ES for symbolic files and -EB for binary files, e.g. a *WRITE EDA SYMB "VOTE" writes a file with external file name VOTE-ES, which can be read as *READ EDA "VOTE". Important: as the use of suffixes on UNIVAC is somewhat awkward, i.e. an "artificial" suffix is added to the file name (and is not a UNIVAC feature) problems arise when you do not omit the suffixes in the file name specification: omit the point from file names, otherwise EDA will append its suffix and the resulting file name may be incorrect.

Note also there is an Fortran bug which causes EDA to abort whenever an illegal file name is specified, especially never specify something like *READ EDA "MYFILE.MYEL". [Sperry says, that this is not a bug... as the user is always expected to enter correct file names; therefore the programmer does not need control about such errors... so adapt yourself!

On UNIVAC normally any @ character type terminates a program; to prevent accidental termination of EDA the CLIST mechanism is used to avoid this. If you type any @ character in column 1 of an EDA command line EDA displays

STATEMENT NOT IN CLIST

There are a few exceptions, namely the @ADD and @FIN commands which are always honored and the following EXEC statements causing EDA to terminate abnormally: @LOG, @JUMP, @TEST, @HDG, @SETC, and @MSG, as well as @ENDX.

There is a drawback, because CLIST mode is not terminated by EDA in one instance: if the program is interrupted by the @@X TO combination, i.e. @@X TO, @@X or @@X O (immediately) followed by @@X T; then CLIST mode is not ended and no other EXEC statement or data is accepted except @FIN and @ENDX, where @ENDX is used to terminate CLIST mode, i.e. re-establishing normal mode.

To avoid this, use - if you must - @@X T, followed if necessary by @@X O (to suppress accumulated output) and do not use @@X without parameter (because it implies IOCT).

When sending a file to the printer EDA asks for the name of the printer (device). If you enter an empty line, then EDA takes the default printer. Use HELP SYSTEM to find out about printer names. Any valid print symbiont may be used (note that the names are locally different). Here in Geneva the default printer is PRASC (the ASCII lower case printer).

When a new file should be created and the file already exists, EDA asks if you wish to overwrite the file. On Univac you may also say A for Append, meaning that the output will be added at the end of the file.