Layers question.

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2 total messages Started by John M. Twilley Fri, 20 Nov 1992 03:50

#40

Author: John M. Twilley
Date: Fri, 20 Nov 1992 03:50

11 lines
817 bytes

I was wondering why layers spends so little time transferring data from
host to terminal.  I hooked up a 9600 bps modem, and got no better
throughput than I did at 2400.  Help?

Jack.
(Also, has anyone written a screen-saver for layers?)
-- 
John M. Twilley             | It's only premarital sex if 
nautilus@acm.rpi.edu        | you're going to get married.
twilley@dewey.nusc.navy.mil |                --anonymous

Re: Layers question.

#41

Author: John M. Twilley
Date: Sun, 22 Nov 1992 21:02

46 lines
2539 bytes

In article <19392@smoke.brl.mil> gwyn@smoke.brl.mil (Doug Gwyn) writes:
>In article <+lz1!a@rpi.edu> nautilus@lachesis.acm.rpi.edu (John M. Twilley) writes:
>>I was wondering why layers spends so little time transferring data from
>>host to terminal.  I hooked up a 9600 bps modem, and got no better
>>throughput than I did at 2400.  Help?
>
>If you're using a pty-based layers rather than an xt- or STREAMS-based
>version, the host is being eaten alive by context-switch overhead.
Nope -- xt-based.  Would one of those switches (-h?) help if I put
STREAMS in?
>
>Packet size is also rather small so some of the link bandwidth is
>consumed by packet framing overhead.  I think the 730 supports a
>larger packet size but the host "layers" process might not be using it.
I can't seem to get the packet size to grow -- I don't think the 5620 supports
it.
>
>In the resident terminal emulator mode, the terminal does a lot of work
>per character and so its effective "glass tty" speed is less than one
>would imagine.  This is especially obvious when using Dave Prosser's
>(otherwise very nice) "myx" on a 5620.
Where can I find this "myx"?  Is it vailable from FTP?
>
>I can see a substantial difference between 9600bps and 19200bps links
>between my 630 and a directly-connected Sun-3/50 host.
>
>Note that so-called "9600bps" modems operated over voice-grade phone
>lines, if they depend on statistical data compression, will have less
>effective throughput than that when transmitting random binary data
>instead of highly patterned data.


Also, I often call out from my DMD to other computers through my 3B2.
Does anyone out there have a good terminal program written todo the
following?
 
 - do as much as possible on the DMD's processor, excepting file xfer

 - provide VTx00 emulation (ancorrectly resize the windo, ifnecesarry)

If anyone has any leads, please let me know .....
Jack.
-- 
John M. Twilley             | It's only premarital sex if 
nautilus@acm.rpi.edu        | you're going to get married.
twilley@dewey.nusc.navy.mil |                --anonymous

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