22 Apr
2011
22 Apr
'11
12:54 p.m.
On 4/22/11 3:31 PM, Rob Jarratt wrote:
Why is this relevant to Windows only? SIMH is the pretty much the
same code on all platforms and does not offer VT100 emulation on any
platform as far as I know.
Exactly. The need for a terminal emulator is a limitation of Windows.
SIMH runs in the terminal under which the user started it. On
platforms that have no other way to execute a program, this means some
sort of terminal interface would need to be built into SIMH. When the
Windows "double click" method is used to start SIMH, it uses the same
mostly-useless window interface that cmd.exe brings up. All other
platforms SIMH runs on have the ability to execute a program under a
real terminal interface, whose terminal emulation protocol can be used
to support software running on the emulated systems that make use of
cursor addressing or other advanced terminal features.
If one had a good terminal emulator under Windows, and Windows had the
ability to arbitrarily tie program character I/O to the I/O interfaces
of the terminal emulator (note that "terminal emulator" means "program
that emulates a terminal", not "program that talks to a serial port")
then Windows-based SIMH would have the same capability as the rest of
the world. As far as I'm aware, Windows has no such capability.
This is probably the third time I've explained this. It's a seriously
two-syllable concept that I'm amazed has required even ONE explanation
in a crowd of people who purport to know something about how computers work.
The other area of concern is the terminal interface.
E11 offers
support for VT100 emulation built into the emulator. SIMH does
not.
Once again, this only comes into play if you're using Windows. On
no other platform is this even relevant. Do you mean that E11 (I am not familiar with this
software) offers
VT100 emulation on all platforms except Windows?
No, that wasn't what I meant at all. What I meant was that peoples'
repeated assertions that SIMH not coming with its own bundled terminal
emulator is somehow a "limitation" is complete and utter bunk.
And even THIS only applies when you're working exclusively on the
(emulated) console of the system. This is why Jerome keeps running into
this; his focus is RT-11 which is almost always used exclusively from
the system console. All other mainstream PDP-11 operating systems are
designed for multi-terminal use, and the console is only (supposed to
be) used for maintenance-type stuff like startup and shutdown. You can
map, say, a DH11 to a TCP port, and use a Windows-based terminal
emulator that speaks the telnet protocol to access a "user" (as
distinguished from "console") terminal in such a configuration.
SIMH even supports access to the console itself via a TCP port,
rendering the argument for console terminal emulation even less relevant.
-Dave
--
Dave McGuire
Port Charlotte, FL