TELECOM Digest OnLine - Sorted: Re: Hayes Smartmodems (was Re: Bell Divestiture)

Re: Hayes Smartmodems (was Re: Bell Divestiture)

Robert Bonomi (
Fri, 24 Jun 2005 10:10:43 -0000

In article <>,
<> wrote:

> Fred Atkinson wrote:

>> I got him to describe the setup. Then I asked him how he was making
>> it dial. He told me that he was typing in 'ATD9,' and then the area
>> code and the number.

>> When Hayes designed the Smartmodem, they should have had the unit
>> default to touch-tone instead of outpulsing rotor dialing by default.
>> Incidents like this could have been avoided. I happened to know that
>> this customer's PBX did not support rotary dialing. The 'T' I added
>> to the string switched the unit from default rotary dialing to touch
>> tone. Problem solved.

> I'm confused. IIRC, the command was four characters, either
> ATDT or ATDP. Are you saying it would work with three?

You remember incorrectly. "ATD" was basic "dial" command. It dialed
the number in whatever was the default mode configured for the modem.
OPTIONALLY, you could 'prefix' the number to be dialed with either a
'T' or a 'P' to force dialing in a particular manner. > >Also, for
dialing out of a PBX, wasn't a 'pause' character needed to >allow time
for the second dial tone?

That depended on the PBX. <grin> You could also do it at two separate
commaneds -- e.g:

> Way back then a lot of people still had rotary service and most
> systems supported both. I don't think early on defaulting to pulse
> was such a bad idea for those days.

Entirely correct. tone dialing was ubiquitous at businesses, but did
not have anywhere the same degree of penetration on residential lines.
A lot of people refused to pay the extra per month charge.

> IIRC, Hayes was the leader in modems, but didn't they end up going
> bankrupt? I didn't understand that.

Hayes was the _early_ leader in building affordable modems for the
home/hobby market. they did a poor job of adapting to the changes in
the marketplace, as speeds went above 2400 baud. the 'higher speed'
market became fractured, as there were _not_ any standards to
follow. There were a number of 'proprietary' schemes implemented --
resulting in manufactur A's high speed modem not being able to talk to
manufacturer B's unit, except by falling back to 2400, or maybe 1200.

The Pac Rim 'copycat' manufacturer's came along, and were putting
'price pressure' on the lower end of the line, while 'incompatibility'
problems plagued the high-end sales.

>> [TELECOM Digest Editor's Note: I think we used 'ATT' for tone dialing
>> and 'ATP' for pulse dialing.

If so, it was not a genuine Hayes unit. Some of the copycat
manufacturers did build in those 'shortcut' commands. In the true
Hayes command set, the 'T' or 'P' was part of the 'dialed number', not
part of the command. for modems that 'saved' numbers, for 'speed
dial", or for 'auto-dial', the 'T' or 'P' was kept as part of the
stored number. You just issued an: "AT {mumble} 4" for example, to
speed-dial stored number #4, where the string stored as #4 was "T

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