Synchronous serial Re: E-Mail Formats RE: Future of cctalk/cctech

[Paul Berger]

On 2020-06-18 3:34 p.m., Chuck Guzis via cctalk wrote:
> On 6/18/20 6:06 AM, Peter Coghlan via cctalk wrote:
>
>> and I also have two Nokia DS 60100 baseband modems, one with a V.35
>> interface card and one with an X.21 interface card.  When I hook up the
>> former with the BC19F cable, I can get the lights on the modem to react
>> when I try to access ZSA0: on the MicroVAX.  However, I can't get any
>> reaction when I use the BC19C cable with the latter even when I jumper
>> the modem to take account of the fewer signals available in X.21.  It
>> may be that the BC19C is meant for something other than the DSH/T32...
>> Anyway, this whole line of attack is fairly academic as the modems can
>> only do 48kbps - 160kbps and the maximum for the DSH/T32 seems to be
>> 19200bps.
> We would have been delighted to get 19.2K on our 11/750.  Leased line
> with a Bell 209 modem, 9600 sync.   Back then, that ran about $5K/month
> for the hookup.
>
> --Chuck
>
When I started out in customer service many years ago anything faster 
than 9600 was very rare and even then they where often split off using 
stat muxes or multi-drop lines.  I call one store have a 9600 line back 
to head office in Toronto that served two store controllers, four 3777s 
with 3203 to print orders, one with a tape drive to transmit orders 
entered on a Nixdorf mini, as well as some miscellaneous terminals in 
the local warehouse and order office.  It was not uncommon for users of 
3270 terminals to have the controllers in a few offices sharing a 
multi-drop line, the banks did the same thing with their terminal 
controllers and ATMs.

I also remember some data centers having conditioned dial-up lines that 
included a handset that you could talk on, but it was pretty weird as 
the conditioned lines did not have echo suppressors.

The first banking terminal I worked on where on a multi-drop 300 baud 
async line and I also worked on finance company terminals that where on 
a multi-drop telegraph line at a speedy 75 baud.

Paul.