Will a Wimodem232 work with a Beeb?

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BBCNoob
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Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Sun Mar 04, 2018 9:24 am

I'd like to know a few things...

First a Wimodem232 is one of these - https://www.cbmstuff.com/proddetail.php ... dem232OLED

Would it be possible to wire up the RS432 port on the back of a Beeb to a Wimodem232? If so, how?

Also, is there any software that would allow for terminal use, so you can get on BBS sites.

Coeus
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Re: Will a Wimodem232 work with a Beeb?

Postby Coeus » Sun Mar 04, 2018 9:50 pm

I first read that as WinModem and, of course, a WinModem would not work because it is just a telephone line interface and D/A & A/D and the actual coding and decoding is done in software in the "driver".

But then I read it again and that unit looks like it has a pretty standard modem interface so it will probably work. I don't have the pinout of a standard 25 pin D-type to hand, or for the five pin Domino on the BBC but you should be able to find these. Mostly likely the Beeb is configured as a DTE and the modem as a DCE so the connections should be to like named pins and leave the ones the BBC does not have unconnected.

There is plenty of terminal software for the BBC. See http://mdfs.net/System/ROMs/Comms/ The Master has Terminal built-in.

BBCNoob
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Re: Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Mon Mar 05, 2018 11:00 am

Thank you for the link.

I'll wait until someone gives a known working wiring. I'm too worried of messing something up.

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MartinB
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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Mon Mar 05, 2018 12:11 pm

Do you have the specific pinout for the Wimodem? Basically, you will be only be connecting TxD, RxD, CTS, RTS and Ground to the Beeb and additionally on the modem you may need to link together a couple more signals such as DTR and DSR depending on the RS232 conventions they've used. The pinout ideally needs to show the signal directions (in or out of the modem) because this is often where confusion lurks.

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Re: Will a Wimodem232 work with a Beeb?

Postby Stewie66 » Tue Mar 06, 2018 4:53 am

I have both the Wimodem232 and also the WiFi232

I've tested the Wifi232 with the Beeb and it works great with the various comms software

viewtopic.php?f=3&t=13265&p=176089&hilit=wifi232#p176089

I haven't had chance to test the Wimodmem232 as just moving house but it uses the same form factor, chipset/connector as the Wifi232 modem so don't see any reason why it wouldn't work

Depending on how my unpacking goes may be able to test this weekend

I made my own RS232 cable as couldn't find any Beeb - DB25 modem cables

Regards Stewart

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Re: Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Tue Mar 06, 2018 9:05 am

MartinB wrote:Do you have the specific pinout for the Wimodem? Basically, you will be only be connecting TxD, RxD, CTS, RTS and Ground to the Beeb and additionally on the modem you may need to link together a couple more signals such as DTR and DSR depending on the RS232 conventions they've used. The pinout ideally needs to show the signal directions (in or out of the modem) because this is often where confusion lurks.


Sadly I don't have the pinouts from the WiModem232. Not wanting to sound pedantic, but the WiModem is actually a thing as well. It's meant for the Commodore 8 bit computers. :)

Stewie66 wrote:I have both the Wimodem232 and also the WiFi232

I've tested the Wifi232 with the Beeb and it works great with the various comms software

viewtopic.php?f=3&t=13265&p=176089&hilit=wifi232#p176089

I haven't had chance to test the Wimodmem232 as just moving house but it uses the same form factor, chipset/connector as the Wifi232 modem so don't see any reason why it wouldn't work

Depending on how my unpacking goes may be able to test this weekend

I made my own RS232 cable as couldn't find any Beeb - DB25 modem cables

Regards Stewart


That sounds great! I'll wait on your feedback then. Especially if it works (As you say, it seems most likely), and you let me know what the wiring is, so I can make my own cable as well. I've already got the parts needed. I think it's a soldering job I won't mess up this time.

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MartinB
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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Tue Mar 06, 2018 10:49 pm

BBCNoob wrote:Not wanting to sound pedantic, but the WiModem is actually a thing as well.

Yes, I did know that, I'd already been looking at their website for pinout details - I was just being lazy and I assumed we both knew what we were referring to.... :)

I've looked at other computer types that have successfully used the device and by deduction from those, I think you'll need a cable wired as shown below. I previously mentioned your possibly needing to link some other lines on the modem but according to the manual, these links are already made by default (there are pads for the purpose on the pcb) so there's nothing else that needs doing. The only extra thing you will need to provide is a +5v DC supply to the modem - you could pick this up from the Beeb (internally or via the AUX PSU connector) but it's not obvious (to me anyway) where on the modem this should be connected, presumably you'd find this out from the Wimodem232 documentation.

Anyway, perhaps Stewie66 will come back and confirm that the cable wiring is correct and how/where to connect the 5v supply.


Wimodem232-Beeb x.jpg
Last edited by MartinB on Wed Mar 07, 2018 7:17 am, edited 1 time in total.

Coeus
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Re: Will a Wimodem232 work with a Beeb?

Postby Coeus » Tue Mar 06, 2018 11:53 pm

MartinB wrote:Wimodem232-Beeb.jpg


Martin that looks like an RS232 DTE pinout. How have you established that this the correct one?

I would have expected a modem to be configured as a DCE rather than a DTE which would mean that pin 2 (Tx) would actually be an input because the label refers to the direction of data on the phone line (or from the perspective of the DTE) so the BBC's TX line would be connected to the modem's TX line, not to RX. Likewise TX would be an output from the modem and should be connected to the BBCs TX line. Crossing them is what you'd do if connecting two DTEs back to back.

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MartinB
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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Wed Mar 07, 2018 12:11 am

Ah, I think you’re right of course - thanks! I spotted one of the modems plugged directly into to an Amiga 1200 and so used that configuration but stupidly, I’ve shown the Amiga side when I should have reversed it for the modem... #-o

Ignore the above, I’ll re-draw it tomorrow but it’ll just amount to reversing pins 2 & 3 and pins 4 & 5 at the modem end....

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Re: Will a Wimodem232 work with a Beeb?

Postby crj » Wed Mar 07, 2018 1:35 am

I never understood why, given domino DIN plugs can be connected in two orientations, Acorn didn't arange CTS, RTS, TXD and RXD such that turning the plug through 180° swapped between normal and null modem. It would have avoided a lot of heartache!

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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Wed Mar 07, 2018 7:15 am

Here's the corrected diagram....


Wimodem232-Beeb a.jpg


Don't forget though as I said above, the modem also needs +5v from somewhere.

.

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Re: Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Wed Mar 07, 2018 7:40 am

Thanks!

It's powered by a mini USB. I already have a 5V 2A plug for it. Way overkill, but it's what I had laying around.

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Re: Will a Wimodem232 work with a Beeb?

Postby Stewie66 » Wed Mar 07, 2018 10:46 am

Hi, still unpacking :-)

The cable wiring looks good, the only addition I did was link pins 6,8,20 together on the DB25 plug

My cable was based on the info from sparrows webpage for a PC/BBC serial cable but with RTS/CTS and TX/RX swapped as per your diagram

http://www.sprow.co.uk/bbc/extraserial.htm#Crossover

I power the modems from a USB hub

Cheers
Stewart

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Re: Will a Wimodem232 work with a Beeb?

Postby dominicbeesley » Wed Mar 07, 2018 12:09 pm

I'm interested to know is there still and active BBS scene? If so how does one find out where they are?

I'm sure I've still got a few modem's kicking around somewhere...

D

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MartinB
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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Wed Mar 07, 2018 12:21 pm

Stewie66 wrote:The cable wiring looks good, the only addition I did was link pins 6,8,20 together on the DB25 plug

According to the Wimodem232 manual, DTR and DSR are linked by default on the modem pcb via configurable links so I don't believe any plug linking should be necessary for RTS/CTS operation with a Beeb but I don't have one of these modems to test that for sure.

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Re: Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Thu Mar 08, 2018 9:30 am

Eureka!

Thank you to everyone that pointed me in the right direction!

Especially MartinB for showing the wiring diagram.

I've created the cable as shown. Nothing extra, no pin to pins on the 25pin side. Just 5 wires.

For now, I've only used the built in terminal of the BBC Master, but I've been able to do the ATZ and the ATDT commands, and actually connected to a BBS site.

How do I use the comms roms that Coeus linked me to?

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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Thu Mar 08, 2018 12:21 pm

I've always used Commstar but there may be better. You can get the original Commstar manual here (scroll down to Pace Commstar) though there may be later versions of the rom on MDFS with features not therefore documented in this version of the manual.

(There may also be manuals available at that 8bs link for some other of the comms roms on MDFS.)

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Re: Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Thu Mar 08, 2018 12:30 pm

Thanks.

Can you let me know how do I go about using roms that are actually files?

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Re: Will a Wimodem232 work with a Beeb?

Postby MartinB » Thu Mar 08, 2018 12:42 pm

You have some sideways ram on a Master by default, although there are links that allow this to be selected as physical roms or sideways ram but let's assume yours is set to ram.

If you download one of those roms as an 8k or 16k image to a floppy disc (if you have one) or to your Datacentre, you should be able to load it into ram using *SRLOAD <rom file name> 8000 4 where 4 is the sideways ram bank id. After loading, press <Ctrl><Break> and type *HELP and you /should/ see the rom listed with the other resident roms.

If you first type *ROMS <Return>, I think you should see a list of rom id's and what roms or ram are present therein. If id 4 says ram (though I think this may be just a question mark :-k) use the command line above or, if 4 isn't ram, pick one that is and substitute it's number for the 4 in the command line. I think by default, id's 4 to 7 should be ram....

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Re: Will a Wimodem232 work with a Beeb?

Postby BBCNoob » Thu Mar 08, 2018 9:03 pm

Thank you yet again! :)

So the answer to my Title question is - yes, yes it does, when you get your head around the wiring and getting the software to load up. :)

Just need the Beeb to come back with, "Would you like to play a game?" LOL