caulkins@cdp.UUCP (05/25/90)
I'm looking for a 4800 baud modem. My brief research indicates this is a strange (and maybe non-existent) beast. Lots of 2400s, quite a few 9600s, but no 4800s that I've been able to locate in a day's poking around in trade pub ads. Any suggestions or names of manufacturers would be much appreciated. Dave C cdp!caulkins@arisia.xerox.com
grr@cbmvax.commodore.com (George Robbins) (05/28/90)
In article <1111100006@cdp> caulkins@cdp.UUCP writes: > > I'm looking for a 4800 baud modem. My brief research indicates > this is a strange (and maybe non-existent) beast. Lots of 2400s, > quite a few 9600s, but no 4800s that I've been able to locate > in a day's poking around in trade pub ads. Any suggestions > or names of manufacturers would be much appreciated. Maybe 5-7 years ago, 4800 bps synchronous modems were considered the workhorses for mainframe connections, while 9600 bps modems were starting to take over, but the ~$1/bps pricing for commercial modems made them a but on the pricey side. If you're looking for a synchronous modem, you should be still be able to get them from the mainstream vendors, but are probably better off getting a more recent 9600 bps modem with fallback to 4800 bps if you need that for some obscure reason. If you are looking for an async modem at this speed you're wasting your time and need to pick one of the current 9600/9600+ bps modems, selecting on either on application requirements or commercial vs. consumer quality. -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing: domain: grr@cbmvax.commodore.com Commodore, Engineering Department phone: 215-431-9349 (only by moonlite)
tnixon@hsfmsh.UUCP (Toby Nixon) (05/29/90)
In article <1111100006@cdp>, caulkins@cdp.UUCP writes:
- I'm looking for a 4800 baud modem. My brief research indicates
- this is a strange (and maybe non-existent) beast. Lots of 2400s,
- quite a few 9600s, but no 4800s that I've been able to locate
- in a day's poking around in trade pub ads. Any suggestions
- or names of manufacturers would be much appreciated.
There are several different kinds of 4800bps modems. The most
popular in the USA is the Bell 208; it comes in a half-duplex
version for two-wire lines, and a full-duplex version for four-wire
leased and private lines; it can't run full-duplex on dial-up lines.
CCITT V.27 modems are very similar.
CCITT V.32 also runs at 4800 in addition to 9600, full duplex on
dial-up lines. When V.32 was first standardized in 1984, a few
companies made 4800-only modems, but these days you just don't find
them; they all have 9600, and will interwork with 4800-only V.32
modems.
I think you'll find that 4800bps modems won't be much, if any,
cheaper than 9600s. You certainly won't find any that "split the
difference" between the street prices of 2400 and 9600 modems.
Be careful not to be misled by ads for "4800 baud" modems that are
really 2400bps modems with MNP5. These will only achieve 4800 with
certain kinds of (very compressible) data.
-- Toby
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-----------------------------------------------------------------------------bourman@hpccc.HP.COM (BobbHewlett-PackardCorpNetEngPaloAltoCa.) (05/31/90)
/ hpccc:comp.dcom.modems / caulkins@cdp.UUCP / 6:56 am May 25, 1990 / |I'm looking for a 4800 baud modem. My brief research indicates |this is a strange (and maybe non-existent) beast. Lots of 2400s, |quite a few 9600s, but no 4800s that I've been able to locate |in a day's poking around in trade pub ads. Any suggestions |or names of manufacturers would be much appreciated. | ||Dave C |cdp!caulkins@arisia.xerox.com |---------- | If you need RS366 dialing (bell 801 auto dialer), then look at the Racal Vadic 4850PA. The V.32 (Racal Milgo RMD3222) will soon have a RS366 auto dialer and will work with 4800bps modems. Racal makes a RMD3281 and VA811 that fit in the old 1601 chassis. The VA811 is the 801 auto dialer and the RMD3281 is the V.32 modem card. This will get you 9600bps. Try Dave Sanford at Racal Milgo (408) 432-8008 BOBB