Q68 serial port

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FrancoisLanciault
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Re: Q68 serial port

Postby FrancoisLanciault » Wed Jan 03, 2018 6:34 pm

Peter wrote:If you don't want to use QL-SD, an emulator, or wait for QLNET support on the Q68, the fastest way is probably to ZIP flopppy contents to ramdisk and then simply COPY it to SER1, even without XON/XOFF.
If the QL is the sender, the lack of Q68 hardware handshake does not matter. The Q68 is fast enough to receive at whatever speed the QL can reliably send.


That is exactly what I did (original poster here).
I used QPTI on both the C68 and SGC+Hermes QL. Communication speed was 19200 Bauds. I used the ZMODEM protocol. Overall it went very well. But with the zmodem protocol, the receiver (Q68) needs to send feedback to the sender (QL) after every block acknowledging that it was received correctly. Theses feedback, however short they are, eventually were not received correctly by the QL because of lack of handshaking. On average the problem occurred every 18 blocks or so. So for 1 block out of 18 the QL did not received the confirmation the Q68 had received the block correctly (even though the Q68 did in fact received it correctly) so the QL was re-sending that block again. That slowed the speed a bit to 1.3 kbytes per second instead of about 1.5 kbytes per second, but it was still faster than trying at 9600 bauds.

I guess I should have tried direct communication like:
On the QL:
copy ram1_stuff_zip to ser1ir
On the Q68
copy ser1 to ram1_stuff_zip

This should work at full speed. I will try it tonight. But I like the fact that zmodem check the integrity of the communication.

I was not able the send anything from the Q68 to the QL with QPTI + zmodem, even at very slow speed. For some reason, even though the baud speed was set to 1200 bauds on the Q68, 16k of data was send instantly by the zmodem program to some buffer, inside QPTI or SMSQ\E or the Q68 hardware I don't know. The QL at the other end was receiving the data without problem. But the zmodem program on the Q68 would eventually timed out and exit. Again I will try without QTPI.

I answer to everyone that gave solution to transfer my data from my Mac to the C68, I thank every one of you. But the problem was not really to transfer between Mac and Q68, but from the QL to the Mac. I don't have floppy drive on my Mac and I don't want to buy a USB floppy just to transfer data from the QL. Serial transfer is more adequate in my case.

Peter wrote:This looks like a typical application for QLNET, for which I hope we will get software support this year.
Could you solder the jack socket and the few external components for that purpose (described elsewhere in this forum)?

All the best
Peter


I can indeed built that no problem. In fact, I received a brand new soldering station at Xmas! Let me know when software support is ready. QLnet would indeed be the best solution.

François


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Peter
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Re: Q68 serial port

Postby Peter » Thu Jan 04, 2018 1:36 am

FrancoisLanciault wrote:
Peter wrote:If you don't want to use QL-SD, an emulator, or wait for QLNET support on the Q68, the fastest way is probably to ZIP flopppy contents to ramdisk and then simply COPY it to SER1, even without XON/XOFF.
If the QL is the sender, the lack of Q68 hardware handshake does not matter. The Q68 is fast enough to receive at whatever speed the QL can reliably send.


That is exactly what I did (original poster here).

No, you used ZMODEM protocol, which is bidirectional. Simply COPY, as you wrote later.

FrancoisLanciault wrote:I was not able the send anything from the Q68 to the QL with QPTI + zmodem, even at very slow speed.

Have you tried XON/XOFF?

Peter


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Re: Q68 serial port

Postby Peter » Thu Jan 04, 2018 1:42 am

johnh wrote:What I'm hoping is that, in the future, the community will agree on a standard board connector and then someone will come up with some sort of I/O "hat" that includes the QLNET connector (and perhaps a "proper" USART)...

I think the first one has a good chance, but I don't think a Q68 SER port with hardware handshake is worthwhile. It brings no advantage when communicating with PC/MAC, and the QL SER is so poor, even with handshake, that everyone will prefer QLNET.


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Dave
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Re: Q68 serial port

Postby Dave » Mon Jan 08, 2018 6:45 pm

In the manual it says pins 4 and 7 are pulled up to power a PS/2 mouse.

What voltage are they pulled up to?

How much current can be drawn from these pins to run external devices like mice, serial adaptors, etc?

Are the pins linked internally, or pulled up separately?

I'm looking to draw 150mA @ 3v3 or 100 mA @ 5v from somewhere..


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Dave
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Re: Q68 serial port

Postby Dave » Mon Jan 08, 2018 6:46 pm

Sorry, only asking because my Q68 is being manufactured, so I don't have one to just ask. :D


Derek_Stewart
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Re: Q68 serial port

Postby Derek_Stewart » Tue Jan 09, 2018 9:20 am

Dave wrote:Sorry, only asking because my Q68 is being manufactured, so I don't have one to just ask. :D


Hi Dave,

I am expecting new Q68 PCBs on 22/1/18, I have you noted down as first on the list due to the shipping lost.

I will is either FED-EX or UPS to ship to the USA, seems to not too much more for a 3 days shipping.

I would be interested in what you are going to connect to the Q68 Serial Port.


Regards,

Derek
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Peter
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Re: Q68 serial port

Postby Peter » Tue Jan 09, 2018 10:17 am

Dave wrote:I'm looking to draw 150mA @ 3v3 or 100 mA @ 5v from somewhere..

I don't have the schematics at hand, but surely this is not possible with unchanged the SER port circuitry. Internally, you have the extension bus for 3.3V and the power connector for 5V (details see User's Manual).

Externally, the PS/2 connector can deliver 5V @ >100 mA.

Are you primarily seeking for a solution connecting to SER? If yes, would it be an option to replace one onboard resistor by 0 Ohms?


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Dave
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Re: Q68 serial port

Postby Dave » Tue Jan 09, 2018 9:34 pm

I would like this add-on to be standalone and not require users to open their cases or modify their Q68s.

With Peter's assistance via email, a solution has been found. I'll power the device externally using a simple micro-USB port. Cheap, ubiquitous, small.

More info in 2 days.


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Re: Q68 serial port

Postby johnh » Sat Jan 20, 2018 11:26 am

FrancoisLanciault wrote:I used QPTI on both the C68 and SGC+Hermes QL. Communication speed was 19200 Bauds. I used the ZMODEM protocol. Overall it went very well. But with the zmodem protocol, the receiver (Q68) needs to send feedback to the sender (QL) after every block acknowledging that it was received correctly. Theses feedback, however short they are, eventually were not received correctly by the QL because of lack of handshaking. On average the problem occurred every 18 blocks or so. So for 1 block out of 18 the QL did not received the confirmation the Q68 had received the block correctly (even though the Q68 did in fact received it correctly) so the QL was re-sending that block again. That slowed the speed a bit to 1.3 kbytes per second instead of about 1.5 kbytes per second, but it was still faster than trying at 9600 bauds.

According to the QTPI manual, the ACK mechanism can be disabled by setting the frame size to zero in the ZMODEM prefs.

FrancoisLanciault wrote:I was not able the send anything from the Q68 to the QL with QPTI + zmodem, even at very slow speed. For some reason, even though the baud speed was set to 1200 bauds on the Q68, 16k of data was send instantly by the zmodem program to some buffer, inside QPTI or SMSQ\E or the Q68 hardware I don't know. The QL at the other end was receiving the data without problem. But the zmodem program on the Q68 would eventually timed out and exit. Again I will try without QTPI.

Could the SMSQ/E dynamic serial port buffer be the problem here? It's many years since I used QTPI but I still have the following command in my QPC BOOT file: SER_BUFF 1,800,80

BTW, the QTPI manual states that the program's default serial buffer size is 16KB...

John Hall



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