[HECnet] Arabic / Unicode support on VMS?

[Johnny Billquist]

On 2013-12-18 17:50, Sampsa Laine wrote:
On 18 Dec 2013, at 18:37, Dennis Boone <drb at msu.edu
<mailto:drb at msu.edu>> wrote:

Does VMS support Arabic text in the console (VT-series terminals etc)
or graphical modes (X11)?

In about 1983, I did some work on VMS 3.x systems in Riyadh.   The user
terminals were Tandberg 2200 family devices with Arabic language
support.   I don't recall there being anything special about the
installed VMS: it had no significant localizations in terms of system
messages, etc.   We were able to do mixed English and Arabic text on
these terminals using standard system utilities (EDT), COBOL
applications and the Cincom Total database.   The terminals operated on a
set-shift model, and it seems like maybe the | character was the shift.
Everything was single-byte character sets.   IIRC the terminals dealt
with the Arabic positional shifting character forms.

I suspect this isn't exactly what you're looking for, though.

De

It might be actually, I'd love to be able to type Arabic on my VMS
boxes, we're getting a retrotech crowd together in Egypt and Lebanon.

The problem with Arabic is that each letter has up to four shapes
depending on its position in the word, i.e. the initial, medial, final
and independent.

So for example the letter MEEM (   - looks like a little circle with a
vertical line hanging off it, sometimes) looks like this when attached
to a SEEN (   - three small vertical bumps):

Independent:   
Initial (MEEM-SEEN):    
Medial (SEEN-MEEM-SEEN):      
Final (SEEN-MEEM):    

Are these encoded as four separate characters or is the renderer meant
to figure out the ligatures and render the correct form of MEEM when
presented with it from memory?

I've attached a PNG of the example above in case some of you guys don't
have Arabic fonts :)

I'd say it's safe to assume that VMS do not do any advanced stuff that you're looking for now, Sampsa. You might have a separate application that can understand all this, but VMS itself do not. In general, each byte is one character, and once output, it stays.

Any rendering of characters differently depending on position will either have to be done inside the terminal, or else by special software in VMS, which is not a part of any normal piece.

	Johnny