*****hayes modem history.....

From: Ed Sharpe <esharpe_at_uswest.net>
Date: Mon Sep 29 13:21:46 2003

yep that is the way... but not with the AT commands... amazing that you
were able to remotely control it though through program.
----- Original Message -----
From: "Eric Smith" <eric_at_brouhaha.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk_at_classiccmp.org>
Sent: Thursday, September 25, 2003 11:53 PM
Subject: Re: *****hayes modem history.....


> "ed sharpe" <esharpe_at_uswest.net> wrote:
> > well in looking into the s100 board it seems to indicate that many
many
> > options could be set under program control, however I am still not sure
> > it is the at command set...
>
> As I wrote before, it is not. Definitely. No question about it.
> It doesn't have ANY command set in the sense of sending it a string
> of characters that it would parse as a command. It's a dumb device.
> (And there's nothing wrong with that!)
>
> > maybe it was some binary sent to it.....
>
> If by "sent to it" you mean "the user program fiddles with bits in
> registers using 8080/Z-80 style input and output instructions", yes,
> that is how it is controlled. Want it to pick up the phone line?
> Set a particular port bit. Clear the bit to hang up (or maybe it was
> the other way around). Pulse dial by toggling that bit with the
> appopriate timing. Enable the modulator (transmit) with a different
> bit, and write to the UART to send bytes. Read a bit of a port for
> receive carrier detect. Etc.
>
> > I just
> > wish I checked remember how the micromodem on the apple worked I suspect
> > the same as the s100 board...
>
> Basically the same though the registers are memory mapped since the
> 6502 doesn't have I/O instructions.
>
> However, the Apple version has firmware that makes it easier to use.
> It's still not the AT command set, but from BASIC you type "IN#2" (if
> it was in slot two), then use Control-A as an attention character to
> send it commands from the keyboard. I suppose you probably printed a
> control-A followed by a command in order to control it from BASIC, just
> like printing a control-D followed by a DOS command, but my memory is
> fuzzy on that as I mostly programmed it in assembly.
>
>
>
Received on Mon Sep 29 2003 - 13:21:46 BST