11 Apr
2011
11 Apr
'11
4:36 p.m.
Dave McGuire wrote:
On 4/11/11 7:31
AM, Jerome H. Fine wrote:
SIMH also does the same thing, although I have a
problem with the screen
display since SIMH does not have built-in emulation for the VT100 (or at
least the last time I used SIMH, it did not).
Urr? This is not the responsibility of a processor emulator. At
least it isn't on any sane platform. SIMH (the PDP-11 part of it) spits the characters out
to its
controlling terminal as it receives them from the emulated PDP-11's
console (addr 777566) serial port. As all common CLI access programs
(xterm/gnome-terminal/etc under most Unices including OS X,
additionally Terminal.app and iTerm.app under OS X) all speak ANSI by
default, you get the correct behavior even on the console.
I don't know if the ability of the VT100 to switch character sets for the
Application Keypad is part of ANSI support. Please clarify.
One other point. While RT-11 must have a console, it need not
be at address 777566. The console can also be a DZ or a DH
device. The only common aspect may be ANSI for a VT100 or
the VT52 protocol in the case of that terminal. Also see below
regarding the use of the SL: under all RT-11 consoles (includes
an RT-11 monitor which supports multi-terminal features which
includes DL, DZ and DH hardware).
By the way, I have not actually tested it, but I think that Ersatz-11
also supports the VT52 Application Keypad - which, of course, is
definitely not ANSI.
And the only PDP-11 OS in which one is essentially
*required* to use
the console all the time is RT-11, which is the least-capable of all
of the various PDP-11 OSs anyway, perhaps excluding some very early
stuff like CAPS-11 and DOS-11.
Actually, in order to run RT-11, typing commands from the console does NOT
require anything other than normal characters. The ONLY reason that RT-11
uses (as opposed to NEEDS) the special characters of the Application Keypad
and the ARROW keys is to run SL: (Single Line Editor - similar in many
aspects
to DOSKEY). Since it probably takes me almost an hour to slowly type my
response in just this one case, I find that the ability to use at least
a command
stack (such as RSTS/E in V10.1 and RT-11 starting around V5.03) makes
program development so much faster that I only use SIMH when absolutely
necessary.
So just because RT-11 is "*required* to use the console all the time" is NOT
essential to support the VT100 ability to switch the Application Keypad keys
to support the SL: in RT-11. Such support is only for fellows like me who
can't touch type at an acceptable speed.
(I'm not knocking either Ersatz-11 or RT-11,
because I love 'em both,
but just injecting a little reality here)
Understood. Again I agree. But I am curious, why has SIMH dropped
what little support it did have for the Application Keypad on the VT100?
Also, why has some eager beaver not stepped up to the plate and developed
an option for SIMH to provide that support for RT-11 fellows like myself?
If Ersatz-11 can support the PF1, PF2, PF3 and PF4 keys, I really don't
understand why SIMH can't do the same. In fact, Ersatz-11 supports the
ability to DEFINE any key, so that might be part of the answer. Ersatz-11
also supports multiple consoles. It is likely that John Wilson thought
about
what features a commercial version of Ersatz-11 would require. I notice
that I use those multiple consoles under RSTS/E as well as TSX-Plus. So
those extra features are not limited to be used by just RT-11. Probably
the extra features can be used by RSX-11, but I don't have a bootable
copy available to run.
Jerome Fine