Terminal issues

[Steven Hirsch]

No, I'm not terminal, but I've been fighting with z80pack all evening trying
to get a Linux terminal emulation that cooperates with programs running under
CP/M.

I start the session inside of 'wy60', which is a Wyse-60 emulation (easier to
configure CP/M apps for that as opposed to VT100/xterm). Almost everything is
working correctly except for one thing: Inside an application (e.g. WordStar
or any other editor), BS, Ctrl-H and Del all produce a non-destructive
backspace! At the command line, they work correctly.

Does anyone have an idea why this is happening?

Steve

[Roger Ivie]

On 2011-12-31, Steven Hirsch <snhi...@gmail.com> wrote:
> I start the session inside of 'wy60', which is a Wyse-60 emulation
> (easier to configure CP/M apps for that as opposed to VT100/xterm).
> Almost everything is working correctly except for one thing: Inside
> an application (e.g. WordStar or any other editor), BS, Ctrl-H and
> Del all produce a non-destructive backspace! At the command line,
> they work correctly.
>
> Does anyone have an idea why this is happening?

I am a bit curious about what you mean by "at the command line, they
work properly". If you're talking about stock CP/M 2, pressing delete
should echo the character deleted whereas ^H will cause it to be
erased from the screen (i.e., behave like most everything else and
therefore likely to be thought of as "working properly"). There is
a patch running around that causes CP/M to treat ^H the same as
delete, but the vanilla install doesn't.

My guess would be that your keyboard map has the backspace and delete
keys configured to send ^H. Having the backspace key so configured is
not unusual, but I think having the delete key also so configured is.

I fear you're going to have to read up on xmodmap. I don't do much X
windows work anymore, and I was pretty fuzzy on xmodmap to start with,
so I can't give you much help.

One thing I do expect, however, is that once you get it mapped correctly
for wy60 and z80pack, it's going to be wrong for everything else. Then
you'll get to read up on "stty dec".
--
roger ivie
ri...@ridgenet.net

[Steven Hirsch]

On 12/31/2011 01:22 AM, Roger Ivie wrote:
> On 2011-12-31, Steven Hirsch<snhi...@gmail.com> wrote:
>> I start the session inside of 'wy60', which is a Wyse-60 emulation
>> (easier to configure CP/M apps for that as opposed to VT100/xterm).
>> Almost everything is working correctly except for one thing: Inside
>> an application (e.g. WordStar or any other editor), BS, Ctrl-H and
>> Del all produce a non-destructive backspace! At the command line,
>> they work correctly.
>>
>> Does anyone have an idea why this is happening?
>
> I am a bit curious about what you mean by "at the command line, they
> work properly". If you're talking about stock CP/M 2, pressing delete
> should echo the character deleted whereas ^H will cause it to be
> erased from the screen (i.e., behave like most everything else and
> therefore likely to be thought of as "working properly"). There is
> a patch running around that causes CP/M to treat ^H the same as
> delete, but the vanilla install doesn't.

I left out a critical fact: This is an NZCOM environment with sane command
line behavior. Ctrl-H is a destructive backspace at the CP/M prompt, but not
when in an application like Wordstar.

> My guess would be that your keyboard map has the backspace and delete
> keys configured to send ^H. Having the backspace key so configured is
> not unusual, but I think having the delete key also so configured is.

Right, but that shouldn't matter since they DO work correctly in the emulator
when I'm sitting at the A> prompt.

> I fear you're going to have to read up on xmodmap. I don't do much X
> windows work anymore, and I was pretty fuzzy on xmodmap to start with,
> so I can't give you much help.

As a workaround, I remapped the Delete key to Ctrl-H, Ctrl-G and, as long as I
remember to use it, that works properly inside applications. I think some
debugging of the z80pack simulator will be required to understand what's going
on. I'm thinking of inserting a small piece of code to write the console
output stream to a file. After a few quick checks inside and outside the
application, I'll take a look through it and see if the CP/M app is munging
the terminal control strings.

> One thing I do expect, however, is that once you get it mapped correctly
> for wy60 and z80pack, it's going to be wrong for everything else. Then
> you'll get to read up on "stty dec".

If I was planning to make this a global change, then yes. However this
environment is specific to running the emulator and is setup with a shell
script for that purpose. Won't affect anything else on the box.

Steve

[Roger Ivie]

On 2012-01-01, Steven Hirsch <snhi...@gmail.com> wrote:
> I left out a critical fact: This is an NZCOM environment with sane command
> line behavior. Ctrl-H is a destructive backspace at the CP/M prompt, but not
> when in an application like Wordstar.

According to the patch notes for MS-DOS WordStar 4.0 that I have lying
around, there's a flag named CTLHFL that controls whether ^H is treated
as ^S or DEL. It's recognized by the CP/M WS4.0 WSCHANGE program; it
looks like it defaults to 0 (i.e., WSU.COM has it zero), which means ^H
is supposed to act as DEL.

I don't have older versions of WordStar lying around. You might try
firing up WSCHANGE and seeing how it's set.
--
roger ivie
ri...@ridgenet.net

[Steven Hirsch]

Ah, thanks very much for that bit of information! I suspect the Z-System
utils are doing something very similar.

[Ivan Shmakov]

>>>>> Roger Ivie <ri...@ridgenet.net> writes:
>>>>> On 2011-12-31, Steven Hirsch <snhi...@gmail.com> wrote:

[Cross-posting to news:alt.os.linux, as this seems like an issue
with XTerm.]

>> I start the session inside of 'wy60', which is a Wyse-60 emulation
>> (easier to configure CP/M apps for that as opposed to VT100/xterm).
>> Almost everything is working correctly except for one thing: Inside
>> an application (e.g. WordStar or any other editor), BS, Ctrl-H and
>> Del all produce a non-destructive backspace! At the command line,
>> they work correctly.

>> Does anyone have an idea why this is happening?

> I am a bit curious about what you mean by "at the command line, they
> work properly". If you're talking about stock CP/M 2, pressing delete
> should echo the character deleted whereas ^H will cause it to be
> erased from the screen (i.e., behave like most everything else and
> therefore likely to be thought of as "working properly"). There is a
> patch running around that causes CP/M to treat ^H the same as delete,
> but the vanilla install doesn't.

> My guess would be that your keyboard map has the backspace and delete
> keys configured to send ^H. Having the backspace key so configured is
> not unusual,

Nevertheless, the “preferred” GNU (and GNU/Linux) backspace is
ASCII DEL (AKA ^?, ^8, \x7f), though, somewhat surprising, XTerm
is often configured contrary to this convention.

> but I think having the delete key also so configured is.

Also note that XTerm does a mapping of its own:

--cut: xterm(1) --
backarrowKey (class BackarrowKey)
Specifies whether the backarrow key transmits a
backspace (8) or delete (127) character. This
corresponds to the DECBKM control sequence. The
default (backspace) is ``true.'' Pressing the
control key toggles this behavior.
--cut: xterm(1) --

This behavior could also be toggled with XTerm menu's “Backarrow
Key (BS/DEL) (backarrow key)” option (Ctrl+LeftMouseButton,
IIRC), or, I believe, by editing the resource with editres(1).

[…]

--
FSF associate member #7257

[Steven Hirsch]

On 01/22/2012 06:15 AM, Ivan Shmakov wrote:
> Nevertheless, the “preferred” GNU (and GNU/Linux) backspace is
> ASCII DEL (AKA ^?, ^8, \x7f), though, somewhat surprising, XTerm
> is often configured contrary to this convention.
>
> > but I think having the delete key also so configured is.
>
> Also note that XTerm does a mapping of its own:
>
> --cut: xterm(1) --
> backarrowKey (class BackarrowKey)
> Specifies whether the backarrow key transmits a
> backspace (8) or delete (127) character. This
> corresponds to the DECBKM control sequence. The
> default (backspace) is ``true.'' Pressing the
> control key toggles this behavior.
> --cut: xterm(1) --
>
> This behavior could also be toggled with XTerm menu's “Backarrow
> Key (BS/DEL) (backarrow key)” option (Ctrl+LeftMouseButton,
> IIRC), or, I believe, by editing the resource with editres(1).

Thanks, Ivan.

I eventually found a ZCPR3 termcap for DEC terminals that appears to work
correctly with xterm in its default configuration.

Steve