Atari Pi Modem

Turning a Raspberry Pi into a modem for your Atari Mega STe.

This, truth be told, isn’t quite as straight forward as the internet would have you believe. In my quest to make this work, I

found USB-to-Serial cables that crashed my Raspberry PI, disabled the Pi’s ethernet port, sent my Mega STe into spasms and

even when it suspiciously looked like it might work, it didn’t.

The first hurdle is Serial-to-USB cables. These aren’t as dumb as you might suspect. They have a chip embedded into them,

and how well that chip is supported varies between kernels in Rasbian.

For example, combining a Raspberry PI with the October release of Rasbian and a prolific PL2303 USB-to-Serial cable looked

exactly like it might work, well the Pi didn’t crash, but no: The ST and the Pi flatly refused to work together.

So here is a kit list that I guarantee will work with Mega STe as simply as possible:

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1 x Raspberry Pi 3+ B with SD Card with Raspbian Stretch Lite

o

I’m using the October 2018. Kernel Version 4.14.

o

You don’t need a GUI on the Pi, it can all be done via pretty simple command line.

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1 x RS232 to USB connector. The keyword to look for when buying a cable is: “RS232”.

o

The Atari Mega STe’s serial connector is a 9pin male, so you will need a female 9 pin

connector on you serial cable. (Like the one in picture on the right.)

Also like this:

AMAZON

NB: Anything else leads to sadness. Sadness leads to anger and anger leads to an Atari Mega STe majestically

flying from a 3rd story window. Also known as: the Dark Side.

How does this all work, then?

You connect the serial port on your serial cable into the Atari’s serial port 1, which is directly below the Mega STe’s power

input socket and then you connect the USB end into your Raspberry PI. The Raspberry PI will also needs a connection to your

home network to get to the Internet. Either via an Ethernet cable, which is simply a matter of plugging one end of the

Ethernet cable into your Internet router or network hub/switch and the other end into you Raspberry PI or configure Wi-Fi on

you Raspberry PI. Follow these instructions to enable WiFi on your Raspberry PI.

Wi-Fi Instructions

.

In an nutshell the Atari is simply sending regular modem commands to the the RaspberryPi and the Raspberry Pi is acting like

a gateway, reading the BBS online and translating it back to the Atari in a way it understands.

First, you need to configure the Raspberry Pi.

The first thing is your Raspberry Pi can be too

darn fast. You need to slow it down. You can

ignore this step, but weird things happened when

I ignored it.

Slowing down the Pi is simple.

You must edit the /boot/config.txt on the

Raspberry:

First backup your config.txt file, you know, just in

case, by running the command:

sudo cp /boot/config.txt to /boot/config.old

If you prefer “nano” then good for you, I prefer “vi”

it’s easy enough.

Run this command:

sudo vi /boot/config.txt

use the down-arrow key to get to the very bottom

of the file, then press the ‘a’ key. (Short for append)

now type in:

core_freq=250

Press ESC

Press: : (The colon key)

Type: wq!

…and you’re good to go.

wq! tell’s vi to write the file to disk and quit. if you mess up

at anytime just press ESC, then type :q! to just quit

without writing the file and start again.

reboot your Pi by entering:

sudo reboot

Now all that is necessary is to install the

modem software. It’s a tool called:

tcpser.

Run these commands, in order:

•

sudo apt-get update

•

sudo apt-get upgrade

•

sudo apt install tcpser

Piece of cake, isn’t it?

All that is left, is to run tcpser to act like a modem. This is easy. The most basic command is this:

sudo tcpser -d /dev/ttyUSB0 -s 9600 -l5

Break down of the command:

tcpser is the application

-d flag points tcpser to the USB serial cable device on the Pi

-s flag is the modem speed tcpser is going to run at. 9600 is the default for the VT52 application on the Atari, so

let’s keep it simple.

-l5 flag sets the logging level. Which is kind of cool, as you can see the Atari talking to the Raspberry Pi.

What do you do on the Atari?

Just to see if it’s all working, I recommend using the

VT52.acc that came on the accessories disk for the

Atari Mega STe. Google for “system disks Atari”, I’m

confident you will find it. Copy the VT52.acc to the root

of your boot drive and reboot the ST. This new app will

appear in the “Desk” menu.

Open the Atari VT52 Terminal Emulator

(See right)

Once you open the Atari VT52 Terminal Emulator it will

look like this. If it only ever looks like this, regardless of

what you press or do, something has gone wrong.

Does it work?

(See right)

If you enter the modem command “at” by typing at,

and then pressing [return] the tcpser Raspberry Pi

modem should respond OK.

Okay let’s BBS, baby.

(See right)

To get onto a BBS, we need to tell the modem to

‘dial’ a url. This is relatively easy. My personal

favourite BBS is Star Fleet Command, as it’s run on

an Atari Mega STe.

http://sfhqbbs.org/

Type in the command

atdt

bbs.sfhqbbs.org:5983

That’s all, folks!

Okay, you’re own your own now kid. You can continue

to use the VT52 terminal emulator or you can play

around with terminal applications for the ST. Many of

which automate certain things, and make use of dial

directories and the like. I use Teddy Term, some use

Taz or Neocom. Google around choose what you like.

Common Hiccups or something goes wrong and the

modem stops responding.

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tcpser has crashed. just restart it. It’s pretty

common.

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Serial speeds don’t match. i.e. you changed the

modem speed on the Pi to 19200 but the Atari is

still talking at 9600. Make sure they match.

Pressing the “help” key while in the Atari VT52

Terminal Emulator will open a menu to change

the speed.

•

Occasionally things go wonky. Yes they do. Other

than simply

seeing

the Atari dial into a BBS using

a Raspberry PI, definitely consider getting a WI-FI

modem if you’re going to make a hobby from

using BBS.

Now Open to the public

My Private Computer Nostalgia

3DO ATARI MEGA STE ATARI FALCON AMIGA 1200 PC ENGINE NEO GEO AES SINCLAIR SPECTRUM +3 ATARI JAGUAR SONY PLAYSTATION

The late 1980s and early 1990s were my personal golden age of gaming. I like tinkering with them, I like seeing what they can do and I like making a website. So here we are.