[Simh] PDP8, Adventure, and SIMH

[Bob Supnik]

PDP-8s by default came with ASR/KSR-33 teletypes, which were upper case 
only (and the parity bit forced on). The default terminal option is 
'KSR' to mimic that.

When DEC began building its own terminals, like the LA36 and VT52, they 
offered upper and lower case. The '7b' option is there for that.

Note that if you SET TTI 7b, start OS/8 (at least the version I have), 
and type dir instead of DIR, the command isn't recognized.

/Bob