Article View: comp.sys.ibm.pc
Article #43806Re: Problem: modem errors w/ disk cache
From: Stephen M. Dunn
Date: Fri, 09 Mar 1990 18:00
Date: Fri, 09 Mar 1990 18:00
24 lines
1902 bytes
1902 bytes
In article <42900066@uicsrd.csrd.uiuc.edu> dkchen@uicsrd.csrd.uiuc.edu writes:
$ Well, I use the smartdrv of Windows as disk cache on extended memory.
$ I also noticed the bad block problem when using xmodem and ymodem.
$ Sometimes the error rate can go as high as 20%. However, I never had
$ any problem using these transmitted files even though errors were
$ reported. I use Avatex 2400 external modem, if that matters.
The reason you never had any problems is that xmodem and ymodem are
error-resistant protocols. When they detect an error in a packet, they
request that the transmitter re-send the packet. Therefore, all bad
packets are thrown away and re-sent, leading to a final file which has
no errors in it.
What should concern you is that when you get a 20% error rate, 20% of
your packets are being retransmitted so your downloads are taking quite
a bit longer than they would normally. This may not matter for 50k files,
but if you're downloading a 500k file, for example, and you have a 20%
error rate, you end up spending the same time as it should take for a
600k file!
--
Stephen M. Dunn cs4g6ag@maccs.dcss.mcmaster.ca
<std_disclaimer.h> = "\nI'm only an undergraduate!!!\n";
****************************************************************************
"Oooh yes I need some love" - Rush
Technical Details
Message-ID:
<25F7EF46.10711@maccs.dcss.mcmaster.ca>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!maccs!cs4g6agReferences:
<1421@oak8.UUCP> <42900066@uicsrd.csrd.uiuc.edu>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!maccs!cs4g6ag From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) Newsgroups: comp.sys.ibm.pc Subject: Re: Problem: modem errors w/ disk cache Message-ID: <25F7EF46.10711@maccs.dcss.mcmaster.ca> Date: 9 Mar 90 18:00:38 GMT References: <1421@oak8.UUCP> <42900066@uicsrd.csrd.uiuc.edu> Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) Organization: McMaster University, Hamilton, Ontario Lines: 24