Date   : Mon, 25 Jan 2021 18:17:43 +0000
From   : jess@... (Jessica Rowbottom)
Subject: Completely expanded "Cheese wedge" BBC Micro - just

There were a few other modems which did this sort of thing - the Dacom Demon
II and Designer modems were step-signalled as well, ISTR.

> On 25 Jan 2021,@18:02, Pete Turnbull <pete@...> wrote:
> 
> On 25/01/2021 14:16, Chris Johns wrote:
>> I had rather expected the prestel adapter to be not much more than a
>> modem in a cheese wedge. Was there more to it than that?
> 
> It has an autodialer.  However the mandate was to build a simple dumb 
> modem without any sort of processor, so it had to use a state machine to 
> change modes and do things like going on/off-hook, dialling, etc. 
> Unlike devices such as Hayes Smartmodems which use an ASCII command set 
> to control smart functions, or other modems that use the user port or 
> some other signalling interface for control, only the Tx, Rx, RTS and 
> CTS lines from the RS423 interface were available to control it.
> 
> -- 
> Pete
> Pete Turnbull
> 
> _______________________________________________
> bbc-micro mailing list
> bbc-micro@...
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro