Issue Tx boards discussions

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stephen_usher
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Re: Issue Tx boards discussions

Postby stephen_usher » Mon Dec 02, 2019 7:24 pm

Peter wrote:[
That would also make it fully compatible to Q40, Q60 and Q68. Still I'm reluctant to recommend the PC pinout - I understand the Tx as a strict retro board, so it makes some sense to keep original QL equipment like printers, printer interfaces or QL-taylormade serial cables directly usable.


Were there many peripherals which used 9 pin DIN connector, rather than the modified BT phone plug?

Myself I would think that using a standard 9 pin RS232 pin-out would allow the use of standard, off the peg cables.


tetroid
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Re: Issue Tx boards discussions

Postby tetroid » Mon Dec 02, 2019 8:26 pm

I am sorry, I will answer all questions later.
Now I need to order several T2 boards before new year.

I see various opinions and I think the best choice :

1. To keep microdrives and QL NET.
2. Both SER connectors - Male with pins 2 ( RxD ) and 8 ( CTS ) inputs and 3 ( TxD ) and 4 ( DTR ) outputs ( DTE ). I think any adapters can be made easy.
Aurora have the same pinouts.
3. We have free place and I add the battery backup socket and parts for ZX8302 battery input. These parts are optional.

Does anybody have the QL NET cable pictures or QL NET jack connector picture ? I think this is 2 pin ( not 3 pin ) connector ?

Image


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Cristian
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Re: Issue Tx boards discussions

Postby Cristian » Mon Dec 02, 2019 9:10 pm

tetroid wrote:[b]Does anybody have the QL NET cable pictures or QL NET jack connector picture ? I think this is 2 pin ( not 3 pin ) connector ?

It is a normal audio jack, used for the classic headphones, but mono (not stereo). Also used for the ZX Spectrum cassette recorder input/output.
Image


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dilwyn
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Re: Issue Tx boards discussions

Postby dilwyn » Mon Dec 02, 2019 11:27 pm

To supplement Cristian's cable picture, here's a picture showing both 2-pole jack connectors for the QL-net:
network.jpg
QL network jack sockets


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Peter
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Re: Issue Tx boards discussions

Postby Peter » Wed Dec 04, 2019 11:24 am

tetroid wrote:3. We have free place and I add the battery backup socket and parts for ZX8302 battery input. These parts are optional.

Nice!
tetroid wrote:Does anybody have the QL NET cable pictures or QL NET jack connector picture ? I think this is 2 pin ( not 3 pin ) connector ?

2 pin for the network cable, but of course the jack socket must have a switch to deselect the termination resistor when a cable is plugged in.
So the jack socket will have 3 (or more) pins on the PCB side.


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Peter
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Re: Issue Tx boards discussions

Postby Peter » Wed Dec 04, 2019 11:43 am

stephen_usher wrote:Were there many peripherals which used 9 pin DIN connector, rather than the modified BT phone plug?

"Many" is relative. But they were around in Germany, I recently bought two printer adaptors of that kind.

The PC style pinout is more practical for today of course. It's just that I'd need to distinguish QL and Tx-QL with possible cable confusions. For strict retro that would not be my taste.
(And for modernized retro, I have much better machines anyway.)


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1024MAK
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Re: Issue Tx boards discussions

Postby 1024MAK » Fri Dec 06, 2019 7:36 pm

Further to the debate on the serial port pin-outs:
If there is space on the board, why not have links / jumper shunts to select which signals appear on which pins?

Mark


QL, Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (Sinclair and Acorn)(nearly forgot the Psion's)
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Dave
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Re: Issue Tx boards discussions

Postby Dave » Sat Dec 07, 2019 6:49 pm

Cristian wrote:
tetroid wrote:[b]Does anybody have the QL NET cable pictures or QL NET jack connector picture ? I think this is 2 pin ( not 3 pin ) connector ?

It is a normal audio jack, used for the classic headphones, but mono (not stereo). Also used for the ZX Spectrum cassette recorder input/output.
Image


No, it isn't. Not quite.

An ordinary audio jack is not switched, and does not connect the termination resistor needed at the end of a NET run. The QL sockets internally connect the resistor when the jack is removed.


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Dave
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Re: Issue Tx boards discussions

Postby Dave » Sat Dec 07, 2019 6:50 pm

1024MAK wrote:Further to the debate on the serial port pin-outs:
If there is space on the board, why not have links / jumper shunts to select which signals appear on which pins?

Mark


Because you shouldn't have to open the machine to discover how the ports are configured. They should always be in a known state.


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Cristian
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Re: Issue Tx boards discussions

Postby Cristian » Sun Dec 08, 2019 10:05 am

Dave wrote:No, it isn't. Not quite. An ordinary audio jack is not switched, and does not connect the termination resistor needed at the end of a NET run. The QL sockets internally connect the resistor when the jack is removed.

I respect your great technical knowledge and I admit I'm not an expert.
Still, I've been using a normal audio jack for about 3 years. It's self-made, 10 meters long, and tested also with other people's QLs. I'll take some photos as soon as possible.



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