Date: Tue, 14 Dec 93 04:30:33 PST From: Ham-Digital Mailing List and Newsgroup Errors-To: Ham-Digital-Errors@UCSD.Edu Reply-To: Ham-Digital@UCSD.Edu Precedence: Bulk Subject: Ham-Digital Digest V93 #146 To: Ham-Digital Ham-Digital Digest Tue, 14 Dec 93 Volume 93 : Issue 146 Today's Topics: ATM on Amateur Radio? C SOURCE FOR PBBS?? F6FBB Mailing List How much time does a G3RUH modem take to acquire signal? Send Replies or notes for publication to: Send subscription requests to: Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the Ham-Digital Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-digital". We trust that readers are intelligent enough to realize that all text herein consists of personal comments and does not represent the official policies or positions of any party. Your mileage may vary. So there. ---------------------------------------------------------------------- Date: 13 Dec 93 12:12:49 +1000 From: munnari.oz.au!newshost.anu.edu.au!sserve!hhcs.gov.au!hhcs.gov.au!news@uunet.uu.net Subject: ATM on Amateur Radio? To: ham-digital@ucsd.edu In article <2dgp2j$s68@vixen.cso.uiuc.edu> Andy Peterson, peterson@ux1.cso.uiuc.edu writes: > It was my understanding that since ATM does not include any frame sequencing > information, using it on a radio link raw would be non-advantageous at best, Correct.. ATM has NO sequencing information, is it also NOT a reliable transport. In the world of Voice and Video comms dropping a few cells here and there is of no real consequence. > since if a packet was lost it could not be recovered. Do I understand this > right? I was under the impression that ATM's main purpose is a standard for > encapsulating information inside other error-correcting frames such as X.25 ATM is another L2/L3 protocol running, roughly, at the same level in the ISO stack as AX.25/X.25, Ethernet, Token Ring etc. Carl. -- Carl Makin (VK1KCM) "Speaking for myself only!" makinc@hhcs.gov.au (Internet) / vk1kcm@vk1kcm.act.aus.oc (Packet Radio) 'The best book on programming for the layman is "Alice in Wonderland"; but that's because it's the best book on anything for the layman.' ------------------------------ Date: 11 Dec 1993 01:58:49 GMT From: juniper.almaden.ibm.com!enge.almaden.ibm.com!enge@uunet.uu.net Subject: C SOURCE FOR PBBS?? To: ham-digital@ucsd.edu In article <755551884snz@imcldn.demon.co.uk>, Michael P Simkins wrote: >In article <931209.73944.TGOODIN@delphi.com> TGOODIN@delphi.com writes: > >> I am looking for C Sources for any kind of PBBS for Packet that I might >> be able to compile for use in my unix (ATT 3B2) machine. >> Tim > >The only one I can think of offhand was an early version of CBBS - If anyone >else knows of something, please let me know, I would be interested too... >-- It doesn't fit all your requirements but the source code for the AA4RE BBS is available. Its about 80,000 lines of Borland Turbo Pascal 7. I think the released version 2.12 source is on the various ftp servers. The beta versions I hand out personally so you know what you are getting. Roy Engehausen, AA4RE enge@almaden.ibm.com ------------------------------ Date: Mon, 13 Dec 93 00:52:19 MST From: library.ucla.edu!agate!howland.reston.ans.net!cs.utexas.edu!asuvax!ennews!stat!david@network.ucsd.edu Subject: F6FBB Mailing List To: ham-digital@ucsd.edu luru@stekt6.oulu.fi (Ari Husa) writes: > In article david@stat.com (David Dodell) writes: > > Welcome! > > You have joined the f6fbb-list@stat.com > > Has F6FBB himself access to the list? He can have access to it, but I do not know his internet account so don't know if he is on it himself. I'm not an active participant, just maintain the list on my machine. david --- Editor, HICNet Medical Newsletter Internet: david@stat.com FAX: +1 (602) 451-6135 Bitnet : ATW1H@ASUACAD ------------------------------ Date: Thu, 9 Dec 1993 17:27:09 GMT From: nntp.ucsb.edu!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!col.hp.com!srgenprp!glenne@network.ucsd.edu Subject: How much time does a G3RUH modem take to acquire signal? To: ham-digital@ucsd.edu ka7oei@uugate.wa7slg.ampr.ORG (ka7oei@uugate.wa7slg.ampr.ORG) wrote: : In practical experience, how long *does* it take for the modem to start : decoding data properly (at 9600 baud?) I don't know about the G3RUH modem but a stock TNC2 with MFJ code in it allows TxD=0 and TXDIDDLE on. TXDIDDLE sends TXCHARS *8 worth of edges to prime the RxClock recovery circuit. With TXCHARS set to 2 and data rate set to 38.4 kbps, packets beginning about 500 microseconds after RTS is asserted (keyup) get through fine. In fact, I think they get through fine with TXCHARS set to 1. I see no reason that it shouldn't be able to do it after about 4 characters delay. I now have data derived DCD circuits in some of the TNCs in which I made the above measurements and haven't remeasured so I can't be sure what they do now. However, watch out for the DCD attack and delay time constants associated with many (TAPR, PacComm...) DCD circuits though. They are apparantly optimized for 1200 bps and can significantly degrade throughput in a faster system. I know this part wasn't your original question but it may be relevant. 73 Glenn n6gn ------------------------------ End of Ham-Digital Digest V93 #146 ****************************** ******************************