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- Xref: sparky comp.dcom.modems:12938 comp.sys.ibm.pc.hardware:23389
- Path: sparky!uunet!uunet.ca!xenitec!zswamp!geoff
- From: geoff@zswamp.UUCP (Geoffrey Welsh)
- Newsgroups: comp.dcom.modems,comp.sys.ibm.pc.hardware
- Subject: Re: V.42bis - on 2400 baud
- Message-ID: <yR5FqB2w165w@zswamp.UUCP>
- Date: Tue, 01 Sep 92 19:36:45 EDT
- References: <amigo.714702563@milton>
- Organization: Izot's Swamp
- Lines: 41
-
- amigo@milton.u.washington.edu (The Friend) writes:
-
- > Few questions about V.42bis 2400 baud modems... firstoff, whats
- > the typical CPS rate on them with zip & gif files? I figure maybe 50%
- > improvement, but its rough-guessing, you only get true 9600 baud output if
- > its straight text files.
-
- Sorry, but precompressed file (including .ZIP and .GIF files), receive
- roughly 20% throughput boost, but it's not from data compression, it's from
- the start and stop bit stripping performed by LAP-M.
-
- > I'm not leaning towards a Zoom modem because recently I got
- > suckered on their V.42bis packaged modem that really is "supported by
- > software" V.42bis.. in other words you have to use the term program included
- > to use the modem at V.42bis.
-
- I'd be suprised if this was true exactly as written. I know of no
- inexpensive Hayes clones (other than Hayes itself) which provide the
- hardware/firmware support to enable LAP-M emulation in software, which would
- be needed to make the software compatible with V.42bis modems (which will
- count on LAP-M before initiating V.42bis).
-
- However, Cardinal modems advertised MNP5 compatibility, even though they
- provided it only through software (MNP, unlike LAP-M, also comes with a fully
- asynchronous mode that doesn't provide the 20% boost on precompressed files,
- but does provide a base for MNP5 compression).
-
- Are you sure that you mean V.42bis, not MNP5?
-
- Also, MNP modems are V.42 compatible, since V.42 includes MNP as a fallback
- protocol... but they're not V.42 compliant, since they do not implement the
- V.42 recommendation in full.
-
- I know people who recommend the ZOOM V.32bis (14400 bps) modems with FAX
- very highly; they have had good connections with USRobotics Courier HST Dual
- Standard 16.8, Hayes Ultra 144, Gandalf 3242, and others.
-
- Geoffrey Welsh, 7 Strath Humber Court, Islington, Ontario, M9A 4C8 Canada
- geoff@zswamp.uucp, [xenitec.on.ca|m2xenix.psg.com]!zswamp!geoff (416)258-8467
- Coincidentally, most people who fight for "fairness" would be
- significantly better off under the system they call "fair"...
-