PE6 Terminal, control character behaviour ?

Buzby

Senior Member
Rich (BB code):
#picaxe 28X2

sertxd("123456789",cr,lf)
sertxd("123456789")
sertxd(8,8,8,8,8,"-")
produces ...

123456789
1234-789

I would have expected the result to be '1234-6789'

What am I doing wrong ?

PE6 control codes.PNG
 

Buzby

Senior Member
It would be really cool if the terminal could utilise control characters better. This is what I expected when I read this line on page 16 of the PE6 document : "Control characters can be optionally used to navigate about the receive box".

I was expecting something that would let me move the cursor up as well as back, or even some VT100 emulation.

I have in the past used a 3rd party terminal to get the type of control needed, but that only worked with a real chip, and meant lots of cable swapping and switching windows.

Could it be possible to have an option in Settings that let the user select an alternative terminal program for PE6 simulation ?.

The PE6 Terminal is the most useful interface to the Simulator, it would be so much more useful if it could act as a 'screen', not just a 'lineprinter'.

Cheers,

Buzby
 

Buzby

Senior Member
I would guess it's some kind of bug or unanticipated interaction with the text display widget. It's something we would have to investigate.
Hi hippy,

Is there any confirmation that this is being investigated ?. I could really do with it working.

Cheers,

Buzby
 

hippy

Senior Member
s there any confirmation that this is being investigated ?. I could really do with it working.
No and I wouldn't hold your breath; creating a VT100 emulator or similar, or even simpler, is something of an undertaking.
 

Buzby

Senior Member
A VT100 emulator is not what I was asking about. I was asking if the stuff already in PE6 is being investigated.

The dropdown in terminal settings has the backspace ( $08 )tickbox, but the result is not as expected.

I don't expect Rev-Ed to wtite a VT100 emulator at all. My suggestion is to allow PE6 to use a 3rd party terminal as an alternative to the built-in version. Interfacing to a 3rd party terminal window ( maybe even something from whatever library of stuff PE6 is built with ) will be much easier than any roll-your-own solution. One of the reasons we were told for developing PE6 was to simplify adding new functionality.

Cheers,

Buzby
 

Buzby

Senior Member
Are Rev-Ed looking into this backspace bug ?

The manual says backspace should work, but it doesn't.
 

Buzby

Senior Member
Are Rev-Ed looking into this backspace bug ?

The manual says backspace should work, but it doesn't.
 

Buzby

Senior Member
Thanks for your support !.

A look through the revision history shows this in PE 6.0.6.3

6.0.6.3
00385 BS [08] special function in Terminal now overwrites characters from current cursor position instead of at end of text.

So it looks like there was a different BS bug at first, but the fix for that bug has introduced another bug !.
 

Goeytex

Senior Member
Many other terminal apps process a BS as "destructive" that is , it overwrtes the previous character as it moves backwards. So I would not call this a bug, but rather an unexpected change. I actually prefer a destructive backspace in most cases.

Ideally the terminal app should allow you to choose whether the BS is destructive or not, but few do.
 

Buzby

Senior Member
The current BS behaviour in PE is neither 'destructive' nor 'non-destructive', it's just plain broken !.

If it was 'destructive', my code in post #1 would result in :
Before : 123456789
....After : 1234-

If it was 'non-destructive', the result would be :
Before : 123456789
....After : 1234-6789

The way it works now :
Before : 123456789
....After : 1234-789

A 'destructive' backspace is called Delete, and is coded in ASCII as chr 127, DEL.
Any terminal emulator that deletes when it should be doing a backspace is wrong, unless is has the option to select 'destructive' or not.

It's been over a year since I pointed out this incorrect behavior of PE, and still no fix for it.
 

Flenser

Senior Member
It's been over a year since I pointed out this incorrect behavior of PE, and still no fix for it.
Buzby,

You reported this terminal issue around the start of the pandemic so keep in mind that while children have not been attending school their teachers have likely not been purchasing many PICAXE products which has led to RevEd needing to put some staff, like Hippy, on furlough.
 
Top