[Info-vax] VMS terminal support (was: AlphaVM-free emulator with all additional peripheral components)

[Stephen Hoffman]

On 2012-08-01 12:53:09 +0000, John E. Malmberg said:

> On 8/1/2012 5:18 AM, Johnny Billquist wrote:
>> 
>> My point was that there is no response "seven bit". And believe me, I've
>> read the manuals backwards and forwards plenty of times.
>> I was curious on how people expected VMS to be able to set eightbit,
>> based on the information in DA1. Maybe something clever that I had
>> missed, but based on your responses, as well as the fact that VMS do not
>> set eightbit even if I have all the capabilities set correctly when I
>> test seems to prove that VMS does indeed not do this, as it can't.
> 
> VMS only seems to be able designed to detect a specific set of VT 
> series terminals that were sold by them or the company that now sells 
> them.  In some cases it can get the geometry of the terminal, in others 
> it can not.

And no support for changing the geometry live, either.
> 
>> If someone else can show VMS doing more, and even better, under which
>> circumstances, I'm curious to look at how it is done. The contents of
>> DA1 does not provide enough information, with the possible exception
>> that if you get a CSI as the eight bit character, that is a pretty good
>> indication that maybe eightbit should be set. (That bit of information
>> is, by the way, what RSX use to set EBC, which is actually exactly how
>> much it really tells.)
> 
> Unfortunately it does not, so creating an algorithm to do so is up to 
> someone else.

Or you do what has been done for ~30 years with VMS, and for longer 
with other platforms.  You read buggy manuals, screw around with the 
host settings, screw around with the wiring, screw around with the 
adapters, screw around with the intermediate networking hardware when 
necessary, chase down your occasional wiring glitch, and then screw 
around with the terminal settings.

Then tussle with the app-level oddities and errors.    Or GNU screen, 
and it's bugs.  Or tmux, where that's available.  Or chasing 
compatibility errors due to vendor compatibility with the bugs that 
were latent in the old (buggy) Hyperterm that was once integrated with 
Microsoft Windows.

Can't say I see the appeal of any of this.

Why do I keep hitting myself with the proverbial hammer: with mentions 
of serial comms and serial cables?  Because it feels so good when I 
stop...


> Serial communications is still used for many consoles and debugging or 
> diagnostic ports.  The terminal server market is apparently alive and 
> well.

Usually at the level of a minimal and possibly buggy VT100, maybe with 
buggy AVO.    This for those devices that are somewhere between a 
product with a JTAG port, and a product with an http/https web 
interface, or USB interface, or that are legacy products.  Microsoft 
was trying to nuke junk I/O back around the Windows XP era, after all, 
and the effort to slay the serial beast has only accellerated.

> One of the complaints about the current generation of low cost tablets 
> is that there is not a serial port that would allow technicians to use 
> them instead of carrying around a laptop.  In some cases an application 
> vendor is making a proprietary cable for serial communications.  But a 
> general solution is not available.

RedPark has available a serial adapter for iPad and iPhone.  ~US$60.  
Some app-related details 
<http://routing-bits.com/2012/07/05/get-console-review-on-the-ipad/> 
with RedPark.

Or connect via a Bluetooth serial adapter, where the widget supports 
Bluetooth Serial Port Profile (SSP) and where an app supports the 
widget.

> The D-Rats Amateur radio system uses serial communications, but can not 
> be used with either a Android tablet or iPad/iPod for that reason.
> 
> The future Microsoft Surface tablet supports a serial port through USB 
> and may be able to capture a bit of that market that has been written 
> off by others.  How big is it?  I do not know.

Haven't tried the USB serial dongle (TrippLite Keyspan USB to Serial 
adapter USA19HS) via an iPad via the camera kit, or (probably more 
likely to work) with the RedPark cable.


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