[Simh] SIMH console settings for escape sequence support

[Mark Pizzolato]

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.  

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.

- Mark