[Info-vax] Reverse telnet to a terminal emulator?

[VAXman- at SendSpamHere.ORG]

In article <j050dd$fh5$1 at speranza.aioe.org>, Snowshoe <no at spam.please> writes:
>On 7/19/2011 5:08 PM, VAXman- @SendSpamHere.ORG wrote:
>> In article<j04nl8$q39$1 at speranza.aioe.org>, Snowshoe<no at spam.please>  writes:
>>> I have done this in the past, sort of. (swiped
>>> SYS$EXAMPLES:ALPHA_LOGGER.C and changed the non-pseudoterminal portion)
>>>   The pseudoterminal part is actually strange code if you have to tamper
>>> with it, but I didn't.
>>
>> What's so strange about it?
>
>[snip code]
>
>The buffers must be in that specially allocated memory which must be 
>page aligned, your data can't be just anywhere. (I got bit by this when 
>one of my changes meant the PTD side tried to access memory outside its 
>special area, and it failed. I had to add an extra copy of my data to 
>its special area)

It does not need to be page aligned.  Your buffers must come from the
memory allocated and assigned to the pseudo-terminal in the PTD$CREATE.
I'd just divvy up the allocated region and put chunks on a queue that
you can allocate and deallocate buffers from.  A piece of cake with a
INSQxx and REMQxx in Macro.


>I/O to a device that doesn't use $QIO. That's kind of weird for VMS. 

Your code will issue $QIOs to the FTAx device.  That's not that weird
for VMS.

The PTD$READ is really simple.  You get handed the data that was seen
at the FTAx device in an AST.  Read the buffer.  Simple.


>I've also tinkered with the TW/PY pseudoterminal pair, long long ago. 
>The PY end used standard QIOs. Want to see what the application just 
>wrote to the terminal? Just $QIO READVBLK to the PY device.

As did I.  The TW/PY pseudo-terminal worked but was much more effort.


>Not super-strange, just not what I expect from VMS.

You don't expect ASTs?

-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

All your spirit rack abuses, come to haunt you back by day.
All your Byzantine excuses, given time, given you away.