[Info-vax] OT: Keypad picture wanted

[Simon Clubley]

On 2020-08-20, Dave Froble <davef at tsoft-inc.com> wrote:
> On 8/20/2020 10:04 AM, Phillip Helbig (undress to reply) wrote:
>> In article <rhlsl4$2kc$1 at dont-email.me>, Dave Froble
>> <davef at tsoft-inc.com> writes:
>>>
>>> I've never considered how such worked, so I don't know what I'm writing
>>> about (what else is new?) but I always considered it a function of the
>>> device (keyboard) not the OS.  I figured that the keyboard sent
>>> different characters, based on the keypad mode.
>>>
>>> Never seemed important to know the inner workings ....
>>
>> IF you have an approximation to the DEC keypad, you can use both numeric
>> and application keypads via an X-terminal, over some terminal-emulator
>> session, or whatever, which is a hint that it is in the application and
>> not in the physical keypad.
>>
>
> As I mentioned, I don't know how it works.  But consider:
>
> The keypad is in application mode.  I want to type in numbers.  It 
> fails. Why?  Seems to me as if different characters are being sent. 

In this case, VMS controls when the keypad is in application mode.

> Note, I can be running WEENDOZE and for example be in NOTEPAD and I 
> still don't get numeric characters.  Sure seems to me to be in the device.
>

In this case, the PC user controls when the keypad is in navigation mode.

The point is that operating systems expect a certain set of capabilities
from the devices that attach to it. PC operating systems do not require
the device to support an application keypad mode, but VMS does.

To make this more clear, in the z/OS world, is the way z/OS interacts
with 3270 terminals a feature of the 3270 terminal or a feature of the
z/OS operating system ?

The answer is the latter. It's a feature of z/OS and z/OS expects that
terminals which attach to it have certain capabilities and a certain way
of operating and that assumption is built into the z/OS terminal
interaction model.

The same is true for VMS.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.