[Simh] SIMH console settings for escape sequence support

[Paul Koning]

> On Dec 31, 2015, at 7:19 PM, Mark Pizzolato <Mark at infocomm.com> wrote:
> 
> On Thursday, December 31, 2015 at 12:18 PM, Paul Koning wrote:
>> I've noticed that terminal handling on the SIMH console with RSTS/E was
>> never quite right; it would not do "set terminal/inquire" and editing keys that
>> produce escape sequences would be mangled.
>> 
>> This turns out to be due to the "printable control characters" configuration
>> setting.  Its default value does not include ESC as a printable character, so it
>> gets discarded rather than sent to the terminal window.
>> 
>> To fix this, use the following SIMH command:
>> 
>> set console pchar=01000023600
>> 
>> With that setting, escape sequences work properly on the console.
>> Something similar probably applies to other operating systems and processor
>> types, if they use escape sequences on the console terminal.  The pchar
>> value is octal on PDP11 and other machines that are conventionally octal; it's
>> hex on VAX and other hex machines, so adjust the "set" command
>> accordingly.
> 
> Thanks for pointing this out.  
> 
> The PCHAR mask is actually only used when the terminal device (console) 
> is in 7B or UC mode.  The PDP11 defaults to 7B mode.  The VAX simulators 
> default to 8B mode.  

Oh.  That doesn't seem to be a documented interaction.

> In the interest of fewer problems in the future for various folks, the 
> default PCHAR mask has now been changed to include ESC and ENQ in 
> addition to the previous BEL, BS, TAB, LF and CR.  The output produced
> by SHOW CONSOLE PCHAR has also been enriched to display the names
> of the characters which are included in the mask.

Nice.  Thanks.

	paul