RE: HTML Emulation WAS: 5250 Data Streams

["Pete Helgren" <pete@xxxxxxxxxx>]

Thanks Nathan...my biggest challenge so far hasn't been the parsing into
HTML, it has been going the other way:  I don't know what the data stream
should look like going back to AS/400.  Should I send everything back or
just the fields, or what?  A clear explanation of the I/O with diagrams,
sample data, etc. would be really helpful but is non-existent.

I'll slog my way through it all....in HEX if I have to.....

Pete Helgren
Timpanogos Technologies



> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Nathan M. Andelin
> Sent: Wednesday, January 21, 2004 11:49 AM
> To: midrange-l@xxxxxxxxxxxx
> Subject: HTML Emulation WAS: 5250 Data Streams
>
>
> Pete,
>
> I scanned the Javadocs for SS-OHIO at:
>
> http://os-ohio.sourceforge.net/javadoc/index.html
>
> The os-ohio interface looks like it was designed for Applets or
> stand-alone
> applications rather than Servlets, but maybe it could be adapted.
>
> A single instance of a Servlet handles requests from multiple concurrent
> users, and individual users may need multiple 5250 sessions, but it looks
> like the os-ohio components maintain the state of just one 5250 session.
>
> I wrote a small RPG program that dumped the 5250 data stream for
> the Sign On
> screen to a file, then displayed the file in HEX mode.  With the help of
> chapter 15 in the 5494 Functions reference, it was possible to see the
> format of the data stream.
>
> Two byte escape sequences are used for screen functions like:
>
> X'0440' - Clear Screen
> X'0411' - Begin Screen Output
>
> Most of the remainder of the data stream defines screen elements - text
> constants, and input fields.
>
> X'11' marks the beginning of both text constants as well as input fields.
> The next two bytes indicate the position (row and column).  The next byte
> contains either the display attribute of a text constant, or a
> byte (x'1D')
> indicating the beginning of an input capable field.  The x'1D' is followed
> by field attributes, field length, and field value.  Simple screens don't
> look to hard to parse.
>
> Hope that helps,
>
> Nathan.
>
>
>
>
> -------- Original Message -----------
>
> date: Tue, 20 Jan 2004 13:29:17 -0700
> from: "Pete Helgren" <pete@xxxxxxxxxx>
> subject: RE: 5250 Data Streams WAS: Arrow keys + scroll keys
>
> The short answer here is that I don't have enough info at the time to
> "report in" although when I have a more functional prototype I can share
> here, I'll actually point back to the tn5250j site at Sourceforge
> where I'll
> post the code.  Scott Klement, who responded earlier, actually brought me
> full circle: I had started at tn5250j, wandered over to the OS-OHIO site,
> built a shell prototype of a 5250 HTML servlet, needed more information on
> using and formatting 5250 data and then James and Booth's
> knowledgeable-looking posts about 5250 data sparked the thought that they
> may have an easier to understand set of documentation for 5250.  So around
> and around we go.  For the list's benefit, I am working on the perhaps
> Quixotic idea that a 5250 emulator can be built using HTML. NOT like WSG
> (which was both ugly and slow) and not screen scraping, just a
> good, basic,
> no bells and whistles 5250 emulator.  The reason: iSeries access is
> bloatware at its best (or worst), Mochasoft TN5250 is excellent and cheap
> but can't be easily integrated into the HTML and java apps we are working
> with, tn5250j is an excellent, open source TN5250 java applet/application
> but using a heavy, client-side JVM gives me the "support willies"
> so rolling
> my own for HTML was the option I arrived at.  The lack of open source,
> "pure" HTML-based Telnet clients (plenty of applets) tells me that this is
> probably a fools errand but, that hasn't stopped me in the past.
>
> The quick impression of OS-OHIO is:  If *I* can write a 5250 servlet
> prototype in just a few hours, it must be easy.  Completing the
> project will
> be the true test of it's usefulness though.
>
> Pete Helgren
>
>
>
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