Cheap web-modem for the beeb/master (and arc if ya like!)

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danielj
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Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Fri May 11, 2018 5:27 pm

So, WiModems, WiFi232s etc... These have been doing the rounds lately, they're around $40-50 + shipping from the US (and you can add VAT+Royal Mail's courtesy fee onto that to). There's not a lot to them, they're all derived from the ESP8266 wifi module and some form of TTL-Serial -> RS232 level shifter. Add in a bit of firmware to allow it to connect over telnet to things and respond to AT commands and you're pretty much up and running.

Now, there's open source firmware for the ESP8266 out there - and I strongly suspect some of these being sold are based on that - but anyway, this combination means it's cheap and pretty easy to get yourself up and running without it costing the earth :) I've tested on a Master, it will work on a beeb, it should work on anything that has an RS232/RS423. Currently hardware handshaking is not implemented, so it gets flakey on the beeb above 2400baud, but I will be looking to do that in the near future :)

You will need:
1x LoLin NodeMCU board with an ESP12E module on it (£5ish shipped from UK, less if you want to wait for one from china)
1x MAX3232 level shifter board - not just the IC on its own! (99p from Hong Kong, probably about £4 from the UK)
1x Domino plug for the beeb's serial...
Some wire for wiring things together.

On your modern computer you need:
The Arduino IDE: https://www.arduino.cc/en/Main/Software
The source for the firmware (I'll be updating this for hardware flow control at some point, and tweaking it as I test it, it's already had a bit of a tweak): https://github.com/stardot/esp8266_modem/tree/v0.1 -nb, this isn't the latest version, but it's the version that was tested with this setup.

On the beeb you need:
Commstar 1.4: http://archive.retro-kit.co.uk/bbc.nvg. ... A-1.40.rom

1st, you need to get the ESP8266 environment set up on the Arduino IDE. Instructions here:
http://www.instructables.com/id/Quick-S ... duino-IDE/

I'd try this as a sample sketch just to make sure you're working OK and able to see wifi networks:
https://github.com/esp8266/Arduino/blob ... FiScan.ino

Once you're sure that you can compile and upload sketches to the NodeMCU board, compile and upload the ESP8266 modem sketch.

Next step is to hook this up to the BBC/Master.

On the domino plug, looking at the solder side, join pins 5/2 (RTS/CTS, red link in my picture), and take lines from GND (centre pin 1), RD (4, Green in my picture) and TD (3, Yellow in my picture):
DSC_3466.JPG
Take TD to the TxD pin on your level shifter and RD to the RxD pin (That's pins 3 and 2 respectively of a 9 pin connector on mine), and GND to GND:
DSC_3467.JPG
On the other side, the MAX3232 will need 3.3V from somewhere (you could snaffle it from the LoLin board) and you can bring the GND from it out to attach to the LoLin board...

Connect the TxD output to the TX pin on the LoLin board (black wire on my picture below), and the RxD output to the RX pin of the LoLin board (brown wire), GND to G (blue wire), and then it's up to you to choose how to power the LoLin board - I've taken 3.3V from my beebscsi (red wire again, but a different red wire to the previous picture) - but you can take 5V and feed that to the VIN pin, or you can just use a USB adapter and power it through that. Entirely up to you. JUST DON'T FEED 5V TO ONE OF THE PINS MARKED 3V! YOU WILL FRY YOUR BOARD!
DSC_3469.JPG
You're now ready to get the thing connected!
Last edited by danielj on Thu Jul 12, 2018 6:47 pm, edited 1 time in total.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Fri May 11, 2018 7:51 pm

Getting online:
Make sure you've got commstar installed, and then run it:
DSC_3471.jpg
Press # to get into terminal mode:
DSC_3473.jpg
Then I to get to the setup screen, change settings to 2400 send, 2400 receive and 8N1:
DSC_3474.jpg
Press C to go into Chat mode and you'll be presented with this screen:
DSC_3475.jpg
Press RST on the LoLin and you should (all things being equal) be greeted with the reset message from the modem:
DSC_3476.jpg
ATWIFISSID,password will get you connected to your wifi network... Check it's worked with ATIP, and then use ADTDaddress:port to connect to the service you want.
DSC_3478.jpg
Press ESCAPE to get back to the main screen and press # to get into Prestel mode. This will reset your comms settings, so before doing anything else press I and change them back to 2400,2400,8N1.

Press C to get back to the comms screen, hit a key (* to redisplay is fairly standard) and you should be greeted by the first frame (or second in this instance):
DSC_3482.jpg
All done :) You're on your own from here :D

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by trixster » Fri May 11, 2018 8:39 pm

This is magic, thanks for posting this daniel :)
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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by myelin » Fri May 11, 2018 8:58 pm

Nice work! Using it to access Teletext is really clever... an internet service that's actually designed for these machines :)
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Most interesting: Arcflash, FX2+PiTubeDirect Tube/Cartridge adapter, USB cart interface.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Fri May 11, 2018 9:02 pm

Thanks :)
I was considering rolling a PCB to tidy it all up, but it's so cheap to do this way, it'd end up actually being more expensive. Besides, the NodeMCU-LoLin thingy is kinda fun anyway and as it's got the serial-usb built in, very easy to program and mess with.

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Fri May 11, 2018 9:17 pm

Oh, and I probably haven't transferred a file to a beeb/master like this since I was 15:
DSC_3470.JPG
:D

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Bat » Sat May 12, 2018 8:57 am

Hi,
I take it you'll need Econet fitted to the beeb?
Would it work with upurs instead?
Cheers,
Gavin :)

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Sat May 12, 2018 9:41 am

You need nothing other than a comms ROM and wifi at home, and some storage device if you want to attempt to download things. No econet needed. The beeb thinks it's using an oldskool modem.

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Sat May 12, 2018 8:19 pm

I've just updated the first post - the ESP8266 appears to be be 5V tolerant but this is somewhat annecdotal - a MAX3232 runs at 3.3V and might be a better bet.

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Bat » Sun May 13, 2018 8:34 pm

Hi,
Just to check I'm getting this right, will these two do?

https://rover.ebay.com/rover/0/0/0?mpre ... 2711990999

https://rover.ebay.com/rover/0/0/0?mpre ... 2750869084

Cheers,
Gavin :)

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Elminster » Sun May 13, 2018 9:01 pm

I have some of these hanging around

https://rover.ebay.com/rover/0/0/0?mpre ... 3074114464

Same chip though

As an aside The RC2014 uses the same WiFi chip in the WiFi expansion board

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by 8bitkick » Mon May 14, 2018 1:49 am

This is awesome... I have one daft question though, have you found a reliable source of RS432 DIN plugs for the beeb?

The only ones I could find say they're domino but the photo disagrees:

http://cpc.farnell.com/deltron-enclosur ... dp/CN00054

The fact I couldn't find them sent me down the UPURS route for serial...

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 5:07 am

Yes they are domino, I got them from cpc :)
UPURS is much faster :)

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 5:10 am

Bat wrote:Hi,
Just to check I'm getting this right, will these two do?

https://rover.ebay.com/rover/0/0/0?mpre ... 2711990999

https://rover.ebay.com/rover/0/0/0?mpre ... 2750869084

Cheers,
Gavin :)
Should do, yup :)

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Bat » Mon May 14, 2018 9:41 am

Hi,
Parts ordered :)
I want to try out the Telstar thingymabob as I've never used anything like that before.
Cheers,
Gavin :)

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by marcusjambler » Mon May 14, 2018 10:22 am

Bits on order... looks like fun :)

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 10:41 am

Things that will make this better: Hardware flow control - I think the ESP8266 should be able to do this at register level, but I need to confirm it!

Overhauling the software, we can add some useful things like "dialling memories" and the facility to tickle it into doing over-the-air updates.

It is open though, if you want to make contributions, download the source and start playing with it :) The more people that do, the better it will become! :D

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Andy1979 » Mon May 14, 2018 2:40 pm

It's a shame my Master Compact is lacks the serial upgrade to make use of this, but plan on building one for use with my Arc and Psion 3a.

There's some discussion of implementing flow control on an Atari forum thread I found when researching a similar project:
http://www.atari-forum.com/viewtopic.ph ... 2&start=75

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 4:24 pm

Andy1979 wrote:It's a shame my Master Compact is lacks the serial upgrade to make use of this, but plan on building one for use with my Arc and Psion 3a.

There's some discussion of implementing flow control on an Atari forum thread I found when researching a similar project:
http://www.atari-forum.com/viewtopic.ph ... 2&start=75

Andy, could you (or someone else) possibly download those for me please? I can't see them as newly registered :(

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by RobC » Mon May 14, 2018 4:40 pm

Andy1979 wrote:It's a shame my Master Compact is lacks the serial upgrade to make use of this...
Mark@Retroclinic has one upgrade kit still available on eBay.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Andy1979 » Mon May 14, 2018 5:26 pm

danielj wrote:
Andy1979 wrote:It's a shame my Master Compact is lacks the serial upgrade to make use of this, but plan on building one for use with my Arc and Psion 3a.

There's some discussion of implementing flow control on an Atari forum thread I found when researching a similar project:
http://www.atari-forum.com/viewtopic.ph ... 2&start=75

Andy, could you (or someone else) possibly download those for me please? I can't see them as newly registered :(

d.
I'm not registered either I'm afraid, it just came up in my searches. Got rid of our Atari when we got the Acorn in 1993. Bit of a bummer that newly registered members can't download files.

@RobC Thanks for the eBay link - I have snapped those up.

Can I run the Comms software from disk (or MMFS when I get round to that), or do I need a ROM?

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by 1024MAK » Mon May 14, 2018 5:48 pm

danielj wrote:
Andy1979 wrote:It's a shame my Master Compact is lacks the serial upgrade to make use of this, but plan on building one for use with my Arc and Psion 3a.

There's some discussion of implementing flow control on an Atari forum thread I found when researching a similar project:
http://www.atari-forum.com/viewtopic.ph ... 2&start=75

Andy, could you (or someone else) possibly download those for me please? I can't see them as newly registered :(

d.
Give me an hour or two...

Mark

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 5:58 pm

Andy1979 wrote: I'm not registered either I'm afraid, it just came up in my searches. Got rid of our Atari when we got the Acorn in 1993. Bit of a bummer that newly registered members can't download files.

@RobC Thanks for the eBay link - I have snapped those up.

Can I run the Comms software from disk (or MMFS when I get round to that), or do I need a ROM?
You can load it into sideways RAM on your compact from disc or MMFS :) Depending on whether you want to spend more than 50p on an solid state solution, my recommendation is to purchase a gotek for £12 and install flashfloppy on it so you can just drop the disc image files straight onto a USB stick without having to muck around with converting anything :) or worry about compatibility issues!

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by 1024MAK » Mon May 14, 2018 9:27 pm

IMG_7063.JPG
schematic
Files attached.

Thanks to czietz over at Atari-Forum for working out how to use flow control :D =D>
[Details are in this post and one a bit further down]

Mark
Attachments
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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 9:44 pm

Thanks Mark! So far so what I've got :D it's the firmware source that's going to be the thing that gives it away.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Mon May 14, 2018 9:46 pm

(I should add that I've got a pcb layout done pending firmware testing. Assumitall is good it'll be unleashed :D)

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by 1024MAK » Mon May 14, 2018 9:59 pm

“I love deadlines. I love the whooshing noise they make as they go by.”
― Douglas Adams

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Tue May 15, 2018 7:02 am

Curses - he only put the binaries up, not the source :( . It's OK though, I'm going to experiment with it at the software level - it looks like the hardware side isn't really properly implemented in the arduino libraries.

d.

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by 8bitkick » Wed May 16, 2018 2:15 am

8bitkick wrote:
danielj wrote:Curses - he only put the binaries up, not the source :( . It's OK though, I'm going to experiment with it at the software level - it looks like the hardware side isn't really properly implemented in the arduino libraries.

d.
Not sure if it helps, but Myelin emulated hardware flow control on Arduino to connect over UPURS:

viewtopic.php?f=3&t=13292

https://github.com/google/myelin-acorn- ... b_port.ino

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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by myelin » Wed May 16, 2018 7:54 am

Look at JGH’s original HostFS source for examples of how to use CTS and RTS on the Beeb’s serial port (the hardware one, as opposed to UPURS).

On the Arduino side, I wouldn’t be surprised if it’s subtly different depending on the MCU!
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Most interesting: Arcflash, FX2+PiTubeDirect Tube/Cartridge adapter, USB cart interface.

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