RE: Re: BIRD53 - IBIS FILE CHARACTER SET

This should make an interesting discussion at the next IBIS Open Forum. My
goal is to have a standard which clearly states which characters are allowed
in an IBIS file. At present, the standard says ASCII, which is a 7-bit code.
Therefore, the wording in this BIRD regarding ASCII is a clarification of
the existing standard, not a change.

Perhaps we should change from ASCII to ISO 8859-1, which supports accented
characters as well (8-bit codes, with the first 128 codes the same as ASCII).
However, this brings up some issues:

  - Will your text editor handle such a file? Apparently recent versions of
    emacs to have ISO 8859-1 support. Also vi on SunOS can handle these,
    if the command

        setenv LC_CTYPE iso_8859_1

    is given before editing. However, use of the LC_CTYPE environment
    variable is not well documented by Sun. Users in the USA would no doubt
    find many difficulties editing such files.

  - Can 8-bit characters appear in the filenames? Yes, if the local OS
    accepts such filenames. Apparently SunOS does. I am not sure about
    other OS's, in particular MS-DOS. Note that item 3 of the general syntax
    rules and guidelines says that filenames "must conform to DOS rules".

  - Will you be able to print such a file? Very few printers in the USA
    directly understand the ISO 8859-1 character set. For some printers,
    including Postscript printers, it will be possible to print the file using
    a special filter. Other printers will not be able to print them.

  - Will you be able to E-mail such a file? Yes, as long as your E-mail
    system accepts attachments of binary files.

Any proposal to change the character set from ASCII to ISO 8859-1 should
address these issues.

***********************************************************************
* Geoffrey Ellis *
* Cadence Design Systems phone: 831-685-6559 *
* 9057 Soquel Drive fax: 831-685-6556 *
* Aptos, CA 95003 E-mail: geoff@cadence.com *
***********************************************************************

>> Only ASCII characters, as defined in ANSI Standard X3.4-1986, may
>> be used in an IBIS file. ASCII is a 7-bit code; 8-bit characters
>> are not allowed.
>
>Is there a technical reason to restrict IBIS to 7-bit codes?
>
>Our in-house IBIS models can contain 8-bit characters - those generated
>by a standard French keyboard - usually in comment fields, or under
>[Source] and [Notes]. I hope that if BIRD53 is accepted, these
>files will pass ibischk, with at worst, the accents being flagged
>simply for information purposes.
Received on Mon Aug 10 11:11:44 1998