Re: Green-screen versus browser

Hi John-

Thanks for your detailed and insightful comments.  I have frequently
referenced the data entry and data stream issues but they slipped by;
the application has multiple multi-page data entry requirements.

I've removed "Gates way".  I have triple 6's in both my office and
numbers; maybe that explains it.  Or it's a case of residual English
major...

-reeve

On 4/25/05, Jones, John (US) <John.Jones@xxxxxxxxxx> wrote:
> Comments in-line...
> 
> John A. Jones, CISSP
> Americas Information Security Officer
> Jones Lang LaSalle, Inc.
> V: +1-630-455-2787  F: +1-312-601-1782
> john.jones@xxxxxxxxxx
> 
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Reeve
> Sent: Sunday, April 24, 2005 10:02 PM
> To: Midrange Systems Technical Discussion
> Subject: Green-screen versus browser
> 
> >>"The problem with green-screen is that the programmer is limited to a
> fixed font size, a limited color palette, essentially no support for
> graphics, only 132 columns (across), only 27 lines (down), and the
> requirement to use a non-standard, usually non-free terminal emulation
> program (Client Access, etc.), which means you can't talk directly to
> many new communications devices like PDA's.<<
> 
> I have a tn5250 client on my PDA.  Many handheld scanners from Symbol,
> etc. have 5250 access.  I think the line about comm devices should be
> removed.  Also, an advantange of a green-screen on a PDA (or in general)
> is that there's less/no temptation for developers to bloat the UI.
> Also, while there are free emulators, Mocha can be had for for $250 for
> a license for an entire company.  Email-based support appears to be
> free.
> 
> >>"There is nothing innately good about browsers; except for Firefox,
> they're bloated with generally useless features, each has its own unique
> characteristics (meaning it doesn't work exactly the same as other
> browsers), and many continue to be a gateway ("Gates way"?) for viruses
> and spyware.<<
> 
> If you want management to take your comments seriously, remove the Gates
> bashing.  I would also remove the 'bloated and generally useless' part.
> I'd probably word it something like this:
> 
> There is nothing innately good about browsers.  Each has there own
> characteristics and compatability issues.  Indeed, within versions of
> the same browser compatability issues often exist.  Browser feature
> support also varies considerably across versions and across operating
> systems; what works on Windows may not work the same on an Apple or a
> Linux-based system.  Web application developers that want to include
> rich content but need to support more than a single version of a single
> browser on a single OS generally devote additional development resources
> to cross-browser and cross-platform support.  Also, browsers are a major
> entry-point for spyware and along with email are major entry points for
> computer viruses.
> 
> Conversely, 5250 has none of these issues.  A 5250 emulator is available
> for all major and most minor computing platforms.  Applications are
> written to the 5250 data stream; compatability issues are extremely
> rare.
> 
> >>"The benefit of browsers is that the programmer has much greater
> control over what the user sees and how the screen works...but it takes
> a lot more programming effort to deliver a browser-based application.
> The basic tradeoff is balancing time-to-deliver (low for green-screen,
> high for browser), function (low for green screen, high for browser),
> and performance (relatively high for green-screen, relatively low for
> browser).<<
> 
> The benefit of browsers is that the programmer has a wider array of
> capabilities that can be delivered as part of the UI, potentially
> enriching the user experience.  However, a browser-based application is
> rarely more efficient as a data entry or reporting tool than a 5250
> application once the user training period is over.
> 
> Both browser and 5250 solutions are host-based computing models.
> Browsers require a smarter client, but with PCs displacing terminals for
> 5250 usage, the point is moot.  On the host side, the 5250 data stream
> takes far less host CPU and RAM resource than a web page that serves
> dynamic content.  Web pages are almost universally larger than 5250
> screens in terms of the data being sent, so a web server will require
> more bandwidth than a 5250-based server.
> 
> Typically, data entry will use less host resources when done via 5250.
> Also, because a data-entry clerk can keep their hands on the keyboard
> and not have to reach for a mouse, and because the communications
> overhead is smaller with 5250, data entry will tend to be faster with a
> 5250-based session.  Both browser and 5250 solutions allow users to
> submit batch work and there is no difference in batch run times since
> the batch process does not use the browser/5250 data stream when
> running.
> 
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