The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: Dan Cross <>
To: John Floren <>
Cc: The Eunuchs Hysterical Society <>
Subject: Re: [TUHS] Anyone have a modem wired up?
Date: Wed, 27 Oct 2021 14:51:05 -0400	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

[-- Attachment #1: Type: text/plain, Size: 1618 bytes --]

On Wed, Oct 27, 2021 at 2:31 PM John Floren <> wrote:

> On Wednesday, October 27th, 2021 at 11:17 AM, Chris Hanson <
>> wrote:
> > Obihai makes some decent, cheap-on-eBay, unlockable/hackable analog VoIP
> boxes that work just fine with not-super-fast modems. You won’t get 56K or
> even 33.6, but 9600-14.4K should be fine and a Telebit Trailblazer probably
> would be too if you want to use UUCP over dialup…
> >
> > — Chris
> I've got a Grandstream HT801 through my ISP ( which works fine
> for voice, and it previously did ok with the modem, but now when I try, I
> start to get garbage soon after the connection establishes (see
> for an example). It happens regardless of
> who I connect to, and seemingly without regard for the connection
> speed--although at 9600, the garbage fills up the screen quite rapidly
> compared to a rather sedate trickle at 4800.

My guess is that the codec it uses is optimized for human speech and gets
confused by the range and levels of data modulation.

My modem-fu is rather weak, so if anyone recognizes what's going on, please
> let me know. I worry that it's just a noisy phone connection, but I was
> under the impression that modems had some sort of error-correction built in
> (this is a SupraFaxModem 288).

This depends very much on the modem. It might be painful, but I wonder what
would happen if you tried it at 1200 or even 300 baud (assuming those are
simple AFSK using two tones as in Bell 103 and 202 schemes).

        - Dan C.

[-- Attachment #2: Type: text/html, Size: 2239 bytes --]

      reply	other threads:[~2021-10-27 18:52 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-23 23:43 John Floren
2021-10-24  0:56 ` Warner Losh
2021-10-24  1:29 ` Kenneth Goodwin
2021-10-24 15:36 ` Dan Cross
2021-10-24 16:14   ` Jon Steinhart
2021-10-24 16:37   ` Larry Stewart
2021-10-24 16:51   ` Dr Iain Maoileoin
2021-10-27 18:17 ` Chris Hanson
2021-10-27 18:29   ` John Floren
2021-10-27 18:51     ` Dan Cross [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \
    --subject='Re: [TUHS] Anyone have a modem wired up?' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).