Could an effective telnet be written?

[pehr anderson]

Dear Prm, 

I think python would be a good tool for this job.

If you are willing to implement all the logic of the
emulated terminal, then you can certainly be satisfied
with the Tkinter text widget.

I was building a shell for morse-code users and was 
not willing to implement all the logic of a terminal.
I tried Tkinter, and realized I'd have to put in all
the terminal behaviors myself, but wanting strict xterm
compatibility, I discovered the zvt widget in the Gnome
libraries.  This widget is used in the standard gnome-terminal
and met all of my needs without *any* additional terminal logic.

If you can translate between 5250 and linux terminal escape codes,
then you may also want the zvt widget. Otherwise you'll likely
be happier with the "pure python" cross-platform solution using Tk.

	-pehr


prm wrote:
> 
> I'm new to Python/TK still.
> 
> Could someone comment on the feasibility of writing a telnet-5250
> emulator using '100% pure python' :) ?
> For those lucky enough not to have experienced a proper 'green screen',
> it is a screen-at-a-time + data-entry-type field
> data+colours/underline/blink attributes + cursor positioning, screen
> save/restore, etc.protocol.
> 
> It is quite involved but performs well on midrange/mainframe situations
> when a number of users transmit packets only when pressing an AID key
> (special function key combination + F1-F24) or pressing Enter.
> 
> I have had a dream of making my own version of the emulator so that I
> can understand and play with it better.
> Orginally I started development in Java but found there was not enough
> leverage in the language over c.
> There is an open sourced c version that I find hard to fathom that works
> fairly robustly under Win and Gnome/Linux.
> 
> If it is easy to create a panel in TK that can switch between displaying
> different non-proportional fonts and switch between 80 columns and 132
> at run time and offer decent support re. key responses function
> key/character events and also loading the panel with text rapidly, I
> would like to give it a go unless someone convinces me it's not a PKAH
> (Python-kicks-ass-here) thing to do...
> 
> Best regards
> Peter Moore
> MJS400