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Re: Issue Tx boards discussions

Posted: Mon Dec 02, 2019 7:24 pm
by stephen_usher
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.

Re: Issue Tx boards discussions

Posted: Mon Dec 02, 2019 8:26 pm
by tetroid
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

Re: Issue Tx boards discussions

Posted: Mon Dec 02, 2019 9:10 pm
by Cristian
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

Re: Issue Tx boards discussions

Posted: Mon Dec 02, 2019 11:27 pm
by dilwyn
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

Re: Issue Tx boards discussions

Posted: Wed Dec 04, 2019 11:24 am
by Peter
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.

Re: Issue Tx boards discussions

Posted: Wed Dec 04, 2019 11:43 am
by Peter
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.)

Re: Issue Tx boards discussions

Posted: Fri Dec 06, 2019 7:36 pm
by 1024MAK
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

Re: Issue Tx boards discussions

Posted: Sat Dec 07, 2019 6:49 pm
by Dave
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.

Re: Issue Tx boards discussions

Posted: Sat Dec 07, 2019 6:50 pm
by Dave
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.