Adrian_Boyko@resbbs.UUCP (Adrian Boyko) (05/26/91)
A friend of mine said that there was some discussion here concerning Compucom's 9600 baud modems. Does this group get archived anywhere? I'd like to go hunting for that discussion. If not, I'd welcome any comments (good or bad) anybody would care to email me on the topic. Thanks, Adrian Boyko
root@zswamp.uucp (Geoffrey Welsh) (05/28/91)
In a letter to All, Adrian Boyko (Adrian_Boyko@resbbs.UUCP ) wrote: >A friend of mine said that there was some discussion here >concerning >Compucom's 9600 baud modems. Does this group get archived >anywhere? I'd >like to go hunting for that discussion. If not, I'd welcome >any comments >(good or bad) anybody would care to email me on the topic. It was a short and relatively calm discussion: GOOD: - It's CHEAP! - They're catching on. - Even if you never connect to another Speedmodem, they're good as a 2400 bps MNP5 modem. - They claim to use a 16550 UART on their modems, though I don't know if it's the reliable National part or one of the flaky substitutes (WD, MX) - FAX model available BAD: - They won't speak 9600 to anything except another Speedmodem - No V.42 - Internal only - They seem to be back-ordered; a friend has had one on order for months - Not full duplex (I suspect half, but asymmetrical has been suggested) - How good can line quality be on a modem whose purpose in life is to do 9600 bps as cheaply as possible? I had expected to be able to render a technical opinion based on observation (as opposed to speculation), but the Speedmodem Combo that my colleague ordered a couple of months back has yet to arrive. -- Geoffrey Welsh - Operator, Izot's Swamp BBS (FidoNet 1:221/171) root@zswamp.uucp or ..uunet!watmath!xenitec!zswamp!root 602-66 Mooregate Crescent, Kitchener, ON, N2M 5E6 Canada (519)741-9553 "He who claims to know everything can't possibly know much" -me
rdippold@cancun.qualcomm.com (Ron Dippold) (05/30/91)
In article <110.28432781@zswamp.uucp> root@zswamp.uucp (Geoffrey Welsh) writes: >In a letter to All, Adrian Boyko (Adrian_Boyko@resbbs.UUCP ) wrote: > > >A friend of mine said that there was some discussion here > >concerning > >Compucom's 9600 baud modems. Does this group get archived >[good and bad] > - How good can line quality be on a modem whose purpose in life is to do >9600 bps as cheaply as possible? Excellent. They use dynamic line impedance matching which seems to do a great job of eliminating even the worst line noise. When I was checking out modems, they had the best noise elimination I saw. PEP was better in really, really horrible situations, but the CompuCom did a better job of getting full speed transmissions noise-free. I ended up with a Dual Standard since line noise isn't usually a problem here and I wanted HST/v.32bis, but I can afford it. -- Standard disclaimer applies, you legalistic hacks. | Ron Dippold
cg108dbd@icogsci1.ucsd.edu (Steve -Social Hacker) (05/31/91)
--=}>> On 28 May 91 14:05:39 GMT, root@zswamp.uucp (Geoffrey Welsh) said: GW> In a letter to All, Adrian Boyko (Adrian_Boyko@resbbs.UUCP ) wrote: [parts deleted..] >A friend of mine said that there was some discussion here >concerning >Compucom's 9600 baud modems. Does this group get archived .. GW> It was a short and relatively calm discussion: GW> GOOD: GW> - It's CHEAP! GW> - They're catching on. GW> - Even if you never connect to another Speedmodem, they're good as a 2400 GW> bps MNP5 modem. Well, I owned one, and I am going to have to disagree with this. I now own a USR HST, and when calling with 2400-MNP5, there is a very noticable difference between a CompuCom and other brands. The CompuCom implementation of MNP5 seems very jerky and filled with (IMHO) overly lengthy pauses. I am familiar with "normal" MNP5 connections, and they are jerky as well, due to the packetting, but much less so. GW> - They claim to use a 16550 UART on their modems, though I don't know if GW> it's the reliable National part or one of the flaky substitutes (WD, MX) GW> - FAX model available From what I was able to tell, they are not using a 16550. I have ran several different UART identifiers, and they all came up with "No 16550". Also, the included MTEZ is supposed to list FIFO in the connection information if a 16550 is detected, and it _does_not_. Again, this is said without any hardware inspection or inside knowledge, but on the software side, I, and all my programs, were unable to find or use a 16550. If anyone knows for sure what is on that card, please post. GW> BAD: GW> - They won't speak 9600 to anything except another Speedmodem GW> - No V.42 GW> - Internal only They have an external model in the making.. Guesstimated release date is approx. late Fall. GW> - They seem to be back-ordered; a friend has had one on order for months GW> - Not full duplex (I suspect half, but asymmetrical has been suggested) According to their documentation, the back-channel is around 350 baud (I can't find the docs now), similar to the HST. GW> - How good can line quality be on a modem whose purpose in life is to do GW> 9600 bps as cheaply as possible? I had no problems with errors on bad lines, but most of my connections are clean. GW> Geoffrey Welsh - Operator, Izot's Swamp BBS (FidoNet 1:221/171) GW> root@zswamp.uucp or ..uunet!watmath!xenitec!zswamp!root One aspect I haven't seen discussed is the actual thoroughput for file transfer. Having owned both the CompuCom and now a USR HST-V.42-14.4K, I was surprised at the dramatic difference. For starters, text reading is MUCH smoother on the HST. The CompuCom exhibits those lengthy packet pauses in 9600 mode as well, and they drive me nuts. As for file xfer, I almost always transfer .ZIP compressed files, so any external protocol they offer (like CCSP) that boasts compression will give me very little, if any. Numbers: On files of medium length (say 250K), clean connections, single-user BBS's, Y-Modem/G HST w/ V.42 at 14.4K: average 1700 cps usually 1620 - 1750 cps I have seen 1750 once or twice 1600 is about the lowest. Most xfers are about 1705-1710 cps. HST without V.42 is less, but I don't have any averages because I do it infrequently. HST at 9600 (old models) is just that, averaging 960 or so cps. (Again, questionable estimate for lack of data.) CompuComm 9600/REL (whatever that means) talking to another of the same on a dedicated BBS: Average 865 cps. usually 850 - 900 cps I did observe 920 once. Speeds as low as 800 - 820 were not uncommon, but less frequent. No, I did not rigorously test over and over on the same files, and this is all just jotting down what the protocol reports as a speed, so it is all very questionable.. BUT for what I do (call BBS's and up&down-load .ZIP files in the 100-300K range) these are very real, and my basis for chosing the HST. Of course, your mileage may, nay *WILL*, vary, so take it all with a grain of statistical salt. I have nothing to do with either CompuCom or USR, etc.. Read my other postings for details on the (excellent) service at CompuCom and other aspects of the modem. Happy Hacking! -Steve -- }>> Steve Haehnichen <<{ shaehnichen@ucsd.edu Disclaimer: UCSD and I do not share any opinions.
root@zswamp.uucp (Geoffrey Welsh) (06/01/91)
In a letter to All, Steve -Social Hacker (cg108dbd@icogsci1.ucsd.edu ) wrote: --=}>> On 28 May 91 14:05:39 GMT, root@zswamp.uucp (Geoffrey Welsh) said: GW> - Even if you never connect to another Speedmodem, they're good as a 2400 GW> bps MNP5 modem. >The CompuCom implementation of MNP5 seems very jerky and filled >with (IMHO) overly lengthy pauses. Funny, I used to say the same about the HST until I got the hang of fine-tuning it. On the other hand, the HST's docs were always good (and they're getting even better), allowing me to do that. GW> - They claim to use a 16550 UART on their modems, though I don't know if GW> it's the reliable National part or one of the flaky substitutes (WD, MX) GW> - FAX model available >From what I was able to tell, they are not using a 16550. I >have ran >several different UART identifiers, and they all came up >with "No >16550". Also, the included MTEZ is supposed to list FIFO in >the >connection information if a 16550 is detected, and it >_does_not_. >Again, this is said without any hardware inspection or >inside >knowledge, but on the software side, I, and all my programs, >were >unable to find or use a 16550. If anyone knows for sure >what is on >that card, please post. As I reported recently, we were unable to identify positively the 40-pin DIP on the board as a UART; I may get around to spending some more time with it and trying a 16550. In the mean time, it is either a 16550 (not so bad, really, since it can be replaced), OR it *emulates* a 16450 (yuch!) >One aspect I haven't seen discussed is the actual >thoroughput for file transfer. Having owned both >the CompuCom and now a USR HST-V.42-14.4K, I was >surprised at the dramatic difference. >For starters, text reading is MUCH smoother on the >HST. The CompuCom exhibits those lengthy packet >pauses in 9600 mode as well, and they drive me nuts. I usually find that disbaling MNP5, forcing smaller packets, and using a computer-modem link rate as close as possible to the modem carrier speed (i.e. don't do talk 19,200 for a 2400MNP link) helps. >As for file xfer, I almost always transfer .ZIP compressed >files, so any external protocol they offer (like CCSP) that >boasts compression will give me very little, if any. I was very disappointed to discover that CSP was an external program. >Numbers: Please keep in mind that the HST you benched is a 14,400 bps device with V.42bis; back in the days of the 9600 bps HST with MNP5, we did up to 1160 CPS with data compression turned OFF (turning it on *slowed* the HST considerably when transmitting precompressed files). Also, please rmember that your benchmark is only as good as the configuration of the modem you're talking to. When I was trying to test my HST, I found that almost no boards (at least for the first while) had theirs properly configured. In particular, hardware handshaking was usually not enabled, menaing that they couldn't lock the port speed higher than the reported CONNECT speed or they'd lose characters with YMODEM-G. >Of course, your mileage may, nay *WILL*, vary, so take it >all with a grain of statistical salt. Done! <grin> -- Geoffrey Welsh - Operator, Izot's Swamp BBS (FidoNet 1:221/171) root@zswamp.uucp or ..uunet!watmath!xenitec!zswamp!root 602-66 Mooregate Crescent, Kitchener, ON, N2M 5E6 Canada (519)741-9553 "He who claims to know everything can't possibly know much" -me
hendricp@wanda.waiariki.ac.nz (06/05/91)
In article <CG108DBD.91May30173937@icogsci6.icogsci1.ucsd.edu>, cg108dbd@icogsci1.ucsd.edu (Steve -Social Hacker) writes: > GW> - They claim to use a 16550 UART on their modems, though I don't know if > GW> it's the reliable National part or one of the flaky substitutes (WD, MX) > GW> - FAX model available > > From what I was able to tell, they are not using a 16550. I have ran > several different UART identifiers, and they all came up with "No > 16550". Also, the included MTEZ is supposed to list FIFO in the I have all the docs, plus their advertising material here, and nowhere can I find any claim to this UART - nor can I find one on the card. > CompuComm 9600/REL (whatever that means) talking to another of the ^^^ > same on a dedicated BBS: > Average 865 cps. > usually 850 - 900 cps > I did observe 920 once. > Speeds as low as 800 - 820 were not uncommon, > but less frequent. Turn off RELiable mode (error correction), and you should get much more. Users on our Opus BBS quite regularly achieve 900-960 cps with ZModem (unless they use an XT to download with :-) --- Peter Hendricks, sysop, The Beast BBS, Rotorua, NZ
caf@omen.UUCP (Chuck Forsberg WA7KGX) (06/08/91)
In article <133.284d5993@wanda.waiariki.ac.nz> hendricp@wanda.waiariki.ac.nz writes:
-Turn off RELiable mode (error correction), and you should get much more. Users
-on our Opus BBS quite regularly achieve 900-960 cps with ZModem (unless they
-use an XT to download with :-)
If they're using a 16550A with ZCOMM or Professional-YAM, they
should be able to get >2000 cps downloading to an XT.
TeleGodzilla is a 4.77 MHz PC with hard disk, and it gets about
2500 cps downloading from Unix at 38k.
"Don't believe everything you read in PC Magazine"cg108w3@icogsci1.ucsd.edu (Steve - Happy Hacker) (06/11/91)
--=}>> On 7 Jun 91 21:59:06 GMT, caf@omen.UUCP (Chuck Forsberg WA7KGX) said: CW> In article <133.284d5993@wanda.waiariki.ac.nz> hendricp@wanda.waiariki.ac.nz writes: CW> -Turn off RELiable mode (error correction), and you should get much more. Users CW> -on our Opus BBS quite regularly achieve 900-960 cps with ZModem (unless they CW> -use an XT to download with :-) CW> If they're using a 16550A with ZCOMM or Professional-YAM, they CW> should be able to get >2000 cps downloading to an XT. CW> TeleGodzilla is a 4.77 MHz PC with hard disk, and it gets about CW> 2500 cps downloading from Unix at 38k. CW> "Don't believe everything you read in PC Magazine" I'm curious to know what kind of files acheive this speed. It smells like protocol compression to me.. :) It's hard to discuss transfer speeds when people quote everything from .ZIP files to 100K of nulls. I try to stick with pre-compressed speed ratings, because this is what the "real world" is for me. If they really get 2500 cps out of binaries, I got a sour one, and will definately try a different one! -Steve -- }>> Steve Haehnichen <<{ shaehnichen@ucsd.edu Disclaimer: UCSD and I do not share any opinions.
caf@omen.COM (Chuck Forsberg WA7KGX) (06/12/91)
In article <CG108W3.91Jun10224829@icogsci1.icogsci1.ucsd.edu> cg108w3@icogsci1.ucsd.edu (Steve - Happy Hacker) writes: ---=}>> On 7 Jun 91 21:59:06 GMT, caf@omen.UUCP (Chuck Forsberg WA7KGX) said: - -CW> In article <133.284d5993@wanda.waiariki.ac.nz> hendricp@wanda.waiariki.ac.nz writes: -CW> -Turn off RELiable mode (error correction), and you should get much more. Users -CW> -on our Opus BBS quite regularly achieve 900-960 cps with ZModem (unless they -CW> -use an XT to download with :-) - -CW> If they're using a 16550A with ZCOMM or Professional-YAM, they -CW> should be able to get >2000 cps downloading to an XT. -CW> TeleGodzilla is a 4.77 MHz PC with hard disk, and it gets about -CW> 2500 cps downloading from Unix at 38k. - -CW> "Don't believe everything you read in PC Magazine" - -I'm curious to know what kind of files acheive this speed. It smells -like protocol compression to me.. :) I was responding to the question of downloading **with an XT**. These are not fast machines, and some comms programs make them a bit quadratic. The 2500cps results were obtained downloading from a Unix system at 38k (no modem). Some files are compressible enough to allow a V.32bis/V.42bis modem to hit 2500 cps throughput. How many you have ready to send somewhere interesting is another question. -- Chuck Forsberg WA7KGX ...!tektronix!reed!omen!caf Author of YMODEM, ZMODEM, Professional-YAM, ZCOMM, and DSZ Omen Technology Inc "The High Reliability Software" 17505-V NW Sauvie IS RD Portland OR 97231 503-621-3406