Re: Ada Terminal Emulator evaluation notes

[clubley@remove_me.eisner.decus.org-Earth.UFP (Simon Clubley)]

In article <3c1f2fe3.0306291949.a7ef41f@posting.google.com>, rossh@zip.com.au (Ross Higson) writes:
> clubley@remove_me.eisner.decus.org-Earth.UFP (Simon Clubley) wrote in message news:<pf60GsI3nRsF@eisner.encompasserve.org>...
> 

[I will reply here for this message as I want to point something out to the
newsgroup in the next paragraph. If you want to do any further followup in
email then feel free to do so.]

> My first reply to this doesn't seem to have appeared, so I'm trying
> again - sorry if that means it appears twice. I'm answering this in
> the newsgroup since Simon raises some good points, but (for future
> adventurers, who I hope won't be put off by Simon's experience !)
> direct email will normally get a faster response.
> 

You seem a bit deflated that I have found a number of problems; don't be. :-)

The display part of your emulator has survived a lot better under VMS than a
number of more higher profile freeware emulators. VMS also has a reputation
for finding problems in emulators that pass other tests. I also want to point
out to the newsgroup that writing a 100% accurate DEC terminal emulator is
actually a hard task and it does not surprise me in the slightest that using
an emulator in a new environment will expose problems.

> I'll try to make my Makefiles more robust. Do you by any chance also
> have GTKAda installed ? This can really mess up GNU Make. Not just my
> stuff - I also cannot build GWindows programs with GTKAda installed.
> Do you think there might be some kind of conspiracy going on here ? :)
> 

Yes, GtkAda is installed.

> You have to set the emulation mode (e.g. to vt100). Use the option
> "/mode" on the command line, such as "comms /port=3 /xin /xout
> /mode=vt100" The emulation mode particularly affects the keyboard, as
> described in Appendix A. The default emulation mode is PC, not VTxxx.
> The advanced menu is enabled by the "/advanced" option. If you enable
> this, you can change the emulation mode from within the program as
> well. For example, use the command "comms /port=3 /xin /xout
> /mode=vt100 /advanced".
> 

I found the comms specific command options on the initial read, and looking
at it again, I have now noticed the pointer to the other part of the manual
containing the other options. You may need to highlight these other options
further as I missed it on a quick read of the documentation. BTW, is there
any reason why you don't just have all the menus enabled ?

>> 6) Pressing Delete sends Backspace (8 decimal) instead of delete
>> (127 decimal). Searching for "Delete" or "Backspace" in the manual did not
>> turn up anything relevant.
>  
> You can send ASCII.DEL by pressing CTRL+backspace (this is described
> in appendix A.2 - I don't know why your search didn't find this). I
> decided not to use the DEL key since it is used as part of the editing
> keypad simulation (required in vt420 mode, also described in appendix
> A). I agree this may be confusing, - I could make the DEL key work as
> you expect in vt100 mode, but I would have to disable it again in
> vt420 mode. One of the problems with the whole keypad emulation is
> that the layout of the IBM keypad is so different to the DEC layout
> that there doesn't seem to be an obvious mapping that suits all modes.
> 

Ah, my DEC background is showing here as there's a terminology confusion here.

When I talk about the Delete key, I am referring to the large key in the upper
right hand of the main keyboard, which is marked Backspace on a PC keyboard,
but which I have always known in recent times as the Delete key (on really
old terminals, it was known as the Rubout key).

On a DEC terminal, that key can be configured to send decimal 127 (Delete) or
decimal 8 (Backspace). On VMS systems that key needs to send decimal 127.

I found the Ctrl+Backspace reference BTW, which is what I ended up using.
What I was looking for was a way to configure Backspace so that it sends
Delete without having to use Ctrl.

My suggested DEC to PC keyboard mapping if you are interested:

Numeric keypad maps one to one with the DEC numeric keypad (including PF1
through PF4 on the top row of the numeric keypad), apart from the PC plus key,
which is mapped to the DEC keypad comma. The DEC keypad minus is ignored.

This choice about which key to drop is made because comma gives you "delete
character" in a DEC editor.

Editing keypad:
	Insert => Insert Here
	Delete => Remove
	Home => Find
	End => Select
	Page Up => Prev Screen
	Page Down => Next Screen

Access the high numbered DEC function keys by using Ctrl. Ie: Ctrl+F6 gives
you F16.

> 
>> 9) Do you have any support for the bell ? VMS operations that normally ring
>> the bell are silent.
> 
> Yes, the emulator supports ASCII.BEL. There must be some other control
> sequences that cause a bell on a real vt100. I'll fix them as I find
> them.
> 

It's just a normal ASCII.BEL. Are you sounding the PC's internal speaker like
MS-Kermit does, or are you sending something out through the sound card, which
may not have speakers attached to it ?

> Also, I think Linux is well provided for in terminal emulation, whereas
> Windows is not. At least, not with non-commercial solutions.
>

Try running some of those Linux emulators against VMS and see how long they
last! :-) The only one that I tried that survived was xterm, and I had to
use a DEC keyboard script with it. In fairness though, it is a year or two
since I last evaluated most of these Linux emulators, so they may have
improved since then.

> 
> Yes, thanks. However, if you can find the time to go at least repeat
> your tests with the emulation mode set to vt100 (which would solve a
> few of the problems) I'd be particularly interested in any more
> information you could give me on the reverse video problem. If you do
> get time, perhaps you could run the program with the
> "/displaycontrols" option enabled, and then save the entire virtual
> buffer to a file and email it to me ?.
> 

I will try and find some time over the next 2-3 weekends to redo some of the
testing. No promises though.

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP       
VMS advocate: One who makes a Mac advocate look like a beginner at advocacy.