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

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Andy1979
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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by Andy1979 » Sun May 20, 2018 3:33 pm

danielj wrote:So I've had a bit of a poke with Communitel
Thanks for trying that out. Sounds like it'll be easier to stick to Commstar.

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

Post by MadeGray » Sat May 26, 2018 9:33 am

Just a thought of mine will look at this weekend unless anyone else has? Just pure laziness but has anyone moded the commstar Rom image to default the send and receive and parity options to N81 9600 ? Just saves the time! I’ve moded Daniels Sketch to add a ATMYFI command that adds in my ssid etc and will probably add some extra commands to load up the common pages such as ATGLASS and ATCC14 etc. Happy to put the modified sketch up it’s not pretty but works!
John Gray

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

Post by danielj » Sat May 26, 2018 10:35 am

If you come up with a generic solution to save autodials in eeprom, we can pull that into the main branch?

d.

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

Post by Andy1979 » Mon May 28, 2018 9:40 pm

Domino DIN plugs arrived and now have this working with flow control.

Not sure what I’m doing wrong but I’m struggling to navigate Prestel once connected - doesn’t seem to respond to pressing # to return to the main menu, hitting enter works but then can’t find my way back from e.g. the news page. Have tried a few different versions of Commstar.

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

Post by danielj » Mon May 28, 2018 10:07 pm

*0# to get back to the main page :) hash being enter in commstar.

d.

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

Post by Andy1979 » Fri Jun 01, 2018 9:07 am

danielj wrote:
Mon May 28, 2018 10:07 pm
*0# to get back to the main page :) hash being enter in commstar.

d.
Thanks for that. Realised that the problem was Commstar not mapping the keyboard correctly on my Master Compact. On the numerical keypad '#' displays an 's' and on the main keyboard Shift-3 generates a '£' sign. All working now I've figured out which key is which!

Also found that Commstar needs DFS otherwise it throws out file system errors when you try to 'Escape' back to the menu. Really wasn't designed with the Master Compact in mind, which isn't surprising given it was written in 1983/4.

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

Post by johnkenyon » Mon Jun 04, 2018 4:14 pm

MadeGray wrote:
Sat May 26, 2018 9:33 am
Just a thought of mine will look at this weekend unless anyone else has? Just pure laziness but has anyone moded the commstar Rom image to default the send and receive and parity options to N81 9600 ? Just saves the time! I’ve moded Daniels Sketch to add a ATMYFI command that adds in my ssid etc and will probably add some extra commands to load up the common pages such as ATGLASS and ATCC14 etc. Happy to put the modified sketch up it’s not pretty but works!
I've done some disassembly of the Commstar 1.40 ROM which reveals two tables of configuration data, which contains amongst other things:

Prestel Mode:
&9497 - Rx Baud rate (=&04 1200)
&9498 - Rx Baud rate (=&01 75)
&9499 - ACIA configuration (= &08 7E1)

Terminal Mode:
&92CD - Rx baud (=&03 300)
&92CE - Rx baud (=&03 300)
&92CF - ACIA configuration (=&14 8N1)

Baud rate values are:
1 - 75bd
2 - 150bd
3 - 300bd
4 - 1200bd
5 - 2400bd
6 - 4800 bd
7 - 9600 bd

I can't remember off the top of my head how I determined the ACIA config values - I assume that 7E1 and 8N1 would probably cover most use cases.

And before you ask, no I haven't tried making the change myself.

/John
(PSThe disassembly is untested - I'd need to format it into an suitable format to feed into an assembler to check that my disassembly works, and it almost certainly contains errors...)
PPS - Commstar 1.40 is only 8k - lots of space for client side hacking (e.g sending init strings, autodialling etc.)

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

Post by pau1ie » Wed Jun 13, 2018 8:08 am

I gave this a go with my bbc master and the terminal program that comes with it. It works!

I had to disable hardware flow control in the sketch (New versions have enabled it). It just crashed the ESP8266 otherwise.

Then I had to do:

*configure baud 5
*configure data 5

and CTRL-BREAK to make it take place. I couldn't get the viewdata service to work, but I connected to a random MUD (I didn't create a character):
IMG_20180613_090011009.jpg
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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Wed Jun 13, 2018 8:32 am

Well done! Concerned the hw flow crashed the esp8266! What implementation of it are you using?

d.

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

Post by pau1ie » Wed Jun 13, 2018 3:57 pm

I'm working on http://bbcmicro.co.uk

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

Post by danielj » Wed Jun 13, 2018 5:48 pm

Did it crash, or did you find you couldn't connect from the beeb? If you've not wired up rts/cts on the beeb end, you need to link rts/cts on the lolin board? Because I'm using exactly the same board and hardware flow control works fine with the beeb :?

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

Post by pau1ie » Wed Jun 13, 2018 6:16 pm

I followed your instructions for wiring things up, so I have the link at the beeb end. It crashed with a message like:

Code: Select all

ets Jan 8 2013,rst cause:4, boot mode:(3,7)
I can get the whole message if you need, it comes up at 115200 baud in the arduino output window no matter what the baud rate is set to in the program. It repeats every few seconds, and nothing on the beeb. It happens even if it isn't attached to the level shifter board.

Cause 4 is watchdog reset according to the documentation (I don't know what that means). I was powering it from my PC using the USB cable, some search results suggest a better power supply is needed, but it works OK with hardware flow control disabled. The test program that lists the access points also works if I set the speed to 2400baud.
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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by hoglet » Wed Jun 13, 2018 6:21 pm

I'd be interested in the whole error log message please.

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

Post by pau1ie » Wed Jun 13, 2018 6:36 pm

If I press reset, I get a line of rubbish, as if it is talking at a different baud rate (Though nothing on the BBC screen - I can't copy the gobbledeygook) then the following repeats every 6 seconds or so (2 iterations pasted, I believe it is identical every time:

Code: Select all

 ets Jan  8 2013,rst cause:4, boot mode:(3,7)

wdt reset
load 0x4010f000, len 1384, room 16 
tail 8
chksum 0x2d
csum 0x2d
v614f7c32
~ld

 ets Jan  8 2013,rst cause:4, boot mode:(3,7)

wdt reset
load 0x4010f000, len 1384, room 16 
tail 8
chksum 0x2d
csum 0x2d
v614f7c32
~ld
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danielj
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Re: Cheap web-modem for the beeb/master (and arc if ya like!)

Post by danielj » Wed Jun 13, 2018 6:40 pm

The watchdog kicks in IIRC if loops are taking too long for the ESP8266 to service background functions. Let me check the latest version from my PC is committed to the repo a bit later.
d.

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

Post by danielj » Wed Jun 13, 2018 7:25 pm

Actually, I remember now, try powering it from an external source when using the hardware flow control - I think you end up with a clash with both things connected at once.

d.

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

Post by 1024MAK » Thu Jun 14, 2018 1:12 am

wdt reset - means watchdog reset - the system restarted after it was reset by the watchdog.

In a computer system, including microcontrollers, you can have a timer circuit. During normal program execution, the program resets (clears) the watchdog counter repeatability during normal program execution. If the program/computer/microcontroller crashes or stalls, the watchdog counter will eventually roll over. At this point, the watchdog will reset the CPU/MPU/microcontroller. But the same thing can happen if too long a time period goes by due to the routing taking too long.

This system is allegedly called watchdog, because a (watch) guard dog never fully sleeps...

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

Post by Stewie66 » Fri Jun 15, 2018 2:08 pm

johnkenyon wrote:
Mon Jun 04, 2018 4:14 pm


I've done some disassembly of the Commstar 1.40 ROM which reveals two tables of configuration data, which contains amongst other things:

I can't remember off the top of my head how I determined the ACIA config values - I assume that 7E1 and 8N1 would probably cover most use cases.

And before you ask, no I haven't tried making the change myself.

/John
(PSThe disassembly is untested - I'd need to format it into an suitable format to feed into an assembler to check that my disassembly works, and it almost certainly contains errors...)
PPS - Commstar 1.40 is only 8k - lots of space for client side hacking (e.g sending init strings, autodialling etc.)
Hi, have made the changes based on the values and locations and tested works

Thanks
Stewie

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