[unix-pc.general] Terminal on tty000

john@spirit.UUCP (John F. Godfrey) (12/01/89)

I recently hooked up a Visentech VS-230 directly to port tty000 on my
3b1.  My machine has 3.5 mb of memory (2 on the main board, 1.5 on an
expansion card) and a 67mb hard drive (ST 4096).  

My question:  is it normal to experience a real loss in normal speed
at either the console or the terminal?  While I was trying to do some
real work :-) my wife was playing mahjongg and we both noticed quite a
drop in performance.  As with my Trailblazer, would the terminal be
better off on the expansion tty that I have left?  viz. tty002?  Does
it matter what type of terminal I say that I am?  I respond at login
to being either vt-100, dt80, or s4.  I am logging in at 9600 baud.

Any suggestions, comments, etc. to help this situation would be
appreciated.

Thanks, John
-- 
John F. Godfrey, Pastor
"Jesus said to him, 'I am the way and the truth and the life.  No man
comes to the Father except through Me'" (John 14:6).
PHONE: 1-(616)-896-8309
NET ADDRESS: john@spirit.UUCP		..sharkey!spirit!john
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gil@limbic.UUCP (Gil Kloepfer Jr.) (12/03/89)

In article <105@spirit.UUCP> john@spirit.UUCP (John F. Godfrey) writes:
>My question:  is it normal to experience a real loss in normal speed
>at either the console or the terminal?  While I was trying to do some
>real work :-) my wife was playing mahjongg and we both noticed quite a
>drop in performance.

Yes....if you were using the terminal and your wife was playing mahjongg
on the console...  Since the window stuff is a driver and runs at kernel
level, at least as far as I can see, it doesn't experience the same
time-slicing that normal user processes experience.  When things are
being displayed on the console, everything on the machine stops while
the character bitmaps are being encoded and placed on the display.

An interesting experiment is to start a UUCP transfer with a telebit, and
watch the lights.   Then cat /etc/termcap on the console.  The lights will
stop blinkin' and so will disk activity and everything else.

> As with my Trailblazer, would the terminal be
>better off on the expansion tty that I have left?  viz. tty002?

I heard yes.  The internal (tty000) port code is less efficient (according
to some inside information) than the code for the expansion ports.

> Does it matter what type of terminal I say that I am?  I respond at login
>to being either vt-100, dt80, or s4.  I am logging in at 9600 baud.

Terminal type doesn't matter...it only tells certain programs which do
screen functions what escape sequences to send to your terminal.

>Any suggestions, comments, etc. to help this situation would be
>appreciated.

Don't use the console display :-)   Seriously though, the solution would
be to NOT produce massive output on the console while you were using the
terminal or modem.  If you replaced the console driver with a user-mode
process that wrote to video memory directly (a la Brian Botton's vidpal
board), there would be less impact on the system as a whole when the console
was used, but in turn the console would be cryingly slow when there was
a CPU-intensive process running.

Hope this helps!

------
| Gil Kloepfer, Jr.
| ICUS Software Systems/Bowne Management Systems (depending on where I am)
| ...ames!limbic!gil

jcm@mtunb.ATT.COM (John McMillan) (12/05/89)

In article <584@limbic.UUCP> gil@limbic.UUCP (Gil Kloepfer Jr.) writes:
>In article <105@spirit.UUCP> john@spirit.UUCP (John F. Godfrey) writes:
:
>> As with my Trailblazer, would the terminal be
>>better off on the expansion tty that I have left?  viz. tty002?
>
>I heard yes.  The internal (tty000) port code is less efficient (according
>to some inside information) than the code for the expansion ports.

	? Huh? Wha? Not that I know of.  Gosh... 'hope I'd know!
	Anyway, the solitary disadvantage of the tty000 is that
	it interrupts at SPL4 while the expansion ports interrupt
	at SPL5.  By the time that becomes significant, your
	barrel's over the falls anyway.  (Tty000 should be
	trivially MORE efficient than the expansion tty's for
	which a BOARD search must be made.)

john mcmillan -- att!mtunb!jcm