Serial port confusion.

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skullandbones
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Re: Serial port confusion.

Post by skullandbones »

Actually, Sinclair's solution was a good idea of having a DTE and a DCE configured serial port because it avoids having an external NULL modem gender changer because the conversion is builtin to the QL.

In the 1980s and early 1990s, if you were not using a 25 pin D type then your solution was proprietary. As there was no official standard for minimal "RS-232" then you had to gamble on being compatible with 3rd party equipment. So providing a DTE and a DCE increased the chances of being compatible with other people's equipment.


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Dave
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Re: Serial port confusion.

Post by Dave »

Who remembers which is which, though? And since the RX side is really one port….


Derek_Stewart
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Re: Serial port confusion.

Post by Derek_Stewart »

Hi,

If the QTPI Manual is consulted, there is complete section on QL Serial port connections.

The SER2 connections:

Code: Select all

SER2     DB9
1. GND    5. GND
2. TxD    3. TxD
3. RxD    2. RxD
4. DTR    7. RTS
5. CTS    8. CTS
6. NC
Works for a Hayes compatible modem and a Serial Mouse.

For connection to SER1, the TxD,RxD and DTR,CTS are reversed:

The SER1 connections:

Code: Select all

SER2     DB9
1. GND    5. GND
2. RxD    3. TxD
3. TxD    2. RxD
4. CTS    7. RTS
5. DTR    8. CTS
6. NC
I have not tested yet.


Regards,

Derek
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t0nyt
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Re: Serial port confusion.

Post by t0nyt »

Derek_Stewart wrote: Fri Mar 11, 2022 6:50 pm Hi,

All sorted now, I forgot all about comms cable.

But looking at the QTPI documentation this defines what is required

Code: Select all

SER2     DB9
1. GND    5. GND
2. TxD    3. TxD
3. RxD    2. RxD
4. DTR    7. RTS
5. CTS    8. CTS
6. NC
note QL Pin 4 is actually a RTS rather than a DTR.

I connected this cable from a Trump Card QL with 8049 to Simulant Wifi Modem, which worked after setting Hayes register S54=2 which is DTR high.

Next step replace 8049 with Hermes.
Is this pinout definitive for connecting a Hayes compatible modem please?

My existing adapter (not been used for anything yet) has the pinout in the image below, which suggests I'll need to re-route the pin 4 from D9 pin 4 to pin 7?

IMG_3748.PNG
IMG_3748.PNG (142.25 KiB) Viewed 162 times

Many thanks


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t0nyt
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Re: Serial port confusion.

Post by t0nyt »

t0nyt wrote: Fri Mar 15, 2024 10:14 am
Derek_Stewart wrote: Fri Mar 11, 2022 6:50 pm Hi,

All sorted now, I forgot all about comms cable.

But looking at the QTPI documentation this defines what is required

Code: Select all

SER2     DB9
1. GND    5. GND
2. TxD    3. TxD
3. RxD    2. RxD
4. DTR    7. RTS
5. CTS    8. CTS
6. NC
note QL Pin 4 is actually a RTS rather than a DTR.

I connected this cable from a Trump Card QL with 8049 to Simulant Wifi Modem, which worked after setting Hayes register S54=2 which is DTR high.

Next step replace 8049 with Hermes.
Is this pinout definitive for connecting a Hayes compatible modem please?

My existing adapter (not been used for anything yet) has the pinout in the image below, which suggests I'll need to re-route the pin 4 from D9 pin 4 to pin 7?


IMG_3748.PNG


Many thanks
I've purchased and wired up a terminal type D9 as per Derek's layout as a starting point, have opted for the terminal type so I can change the cable layout without a soldering iron!

Everywhere I look I see different pinouts for SER2 (Dilwyn's site seems to say Modem should be on SER1 which adds more confusion for me)

The only thing that seems consistent over all sources I've found is Pin 6 and Pin 1

Will try the cable I've made when modem arrives


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