Q68 Serial devices

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Artificer
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Q68 Serial devices

Postby Artificer » Sat Feb 15, 2020 8:22 pm

Question - is it possible to a easily add an additional RS232 serial port to a Q68?

Cheers


Derek_Stewart
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Re: Q68 Serial devices

Postby Derek_Stewart » Sat Feb 15, 2020 9:55 pm

Artificer wrote:Question - is it possible to a easily add an additional RS232 serial port to a Q68?

Cheers

Hi,

The Q68 has an expansion port on the board, which could allow the design of a suitable expansion card.

But, assuming the hardware coukd be interfaced to the Q68 expansion port correctly, a driver would need to written.

There was talk of an expansion card to do this, but it never came to light...


Regards,

Derek
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Peter
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Re: Q68 Serial devices

Postby Peter » Wed Feb 19, 2020 8:46 am

Artificer wrote:Question - is it possible to a easily add an additional RS232 serial port to a Q68?

If you just need an individual solution and we can agree on some other pins you don't need, I could look into this and ask Wolfgang if he's willing to make a little SMSQ/E change for it.
Such a tinkered solution would provide 3.3V TTL level, similar to the Raspberry serial port. Can you add an external RS232 line driver? Or maybe use a Raspberry style SER-USB cable?
You'd need someone with a Lattice programming adaptor for FPGA update.

Let's not talk about which pins, before making sure the rest is viable. Also please tell us your target for the second serial port - it's always better to understand the application before attempting a solution.


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Artificer
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Re: Q68 Serial devices

Postby Artificer » Wed Feb 19, 2020 10:37 am

Peter wrote
"Also please tell us your target for the second serial port - it's always better to understand the application before attempting a solution."


Easily is the key here as the need is minor, and it is because I am lazy.

I have Q68, Q60 and Rpi. The Q68 and Q60 are connected serial to serial with Sernet. Gives the Q68 access to accumulated software on Q60 hard drives and to CDRoms,CF cards and floppy drives. On the Rpi I am developing a python script to catch printer output from the Q60/Q68 serial ports and send to CUPs for wireless printing. Printing of flat files and postscript from the Q68 and Q60 is established and html (and conversion of html to pdf) is virtually there might be finished today as its very simple.

Even though the Q60 is faster I prefer programming on the Q68 as it is silent - no fans but with only one serial port it cannot connect to both the Q60 and Rpi simultaneously and I am always forgetting to rjob sernet before I can print from the Q68 and or I need to switch the serial cable thats all.

In the long run though a python driven bidirectional serial to serial connection with the Rpi may well be very useful for the Q68.

Cheers


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Peter
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Re: Q68 Serial devices

Postby Peter » Wed Feb 19, 2020 11:05 am

Artificer wrote:On the Rpi I am developing a python script to catch printer output from the Q60/Q68 serial ports and send to CUPs for wireless printing.

In this application, I don't see a strong need for a second serial port on the Q68. It is easier to set up an I²C slave on the Raspberry and adapt my Q68 I²C master example to send your printer output via I²C. Just a three wire (two + grounded shield) cable and a C68 software project. No hardware nor FPGA changes. You might want to look here: https://qlforum.co.uk/viewtopic.php?f=20&t=2869&hilit=I2C&start=10#p28317


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Artificer
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Re: Q68 Serial devices

Postby Artificer » Thu Feb 20, 2020 9:23 am

Peter wrote,
It is easier to set up an I²C slave on the Raspberry and adapt my Q68 I²C master example to send your printer output via I²C. Just a three wire (two + grounded shield) cable and a C68 software project.


Thanks for the suggestion but I don't think I'll be doing that soon, I have other software priorities including a Quill doc to postscript filter solution. I have still to learn some postscript. But I2C connection on Rpi is well documented and supported and might be of use for other things.

A further question, why did you not design the Q68 with 2 RS232 ports as had the original QL, Qx0 and Aurora? Did the FGPA board not support more than 1?

Cheers


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Peter
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Re: Q68 Serial devices

Postby Peter » Thu Feb 20, 2020 12:03 pm

Artificer wrote:A further question, why did you not design the Q68 with 2 RS232 ports as had the original QL, Qx0 and Aurora?

It was a space/resource compromise. I wanted a decent metal case, where I can design the panels, and I didn't want it larger. Also, freeing the required FPGA pins for one more SER would have caused a loss somewhere else.
The Q68 has onboard I2C, ethernet and a PS/2 mouse port - which original QL, Qx0 and Aurora have not! I didn't want to lose any of these.

By the way, you are the only one asking for a second SER in years. Request for hardware handshake was much higher.


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bwinkel67
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Re: Q68 Serial devices

Postby bwinkel67 » Thu Feb 20, 2020 7:25 pm

BTW, for $18 currently on eBay they are selling USB to PS/2 converters. These things usually run closer to $100:

https://www.ebay.com/itm/BLACK-BOX-MODEL-KVUSBNF-USB-TO-PS-2-CONVERTER/152400356399

I'm assuming as long as the PS/2 end acts like PS/2 the Q68 cares little about there being a USB keyboard and/or mouse on the other end (as long as no drivers are involved).

Anyone have any luck with these before I invest in one.


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Peter
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Re: Q68 Serial devices

Postby Peter » Fri Feb 21, 2020 12:24 pm

bwinkel67 wrote:BTW, for $18 currently on eBay they are selling USB to PS/2 converters. These things usually run closer to $100

Thanks for spotting this :!:
Indeed it looks like an active converter, which is needed if someone wants to use USB-only devices with the Q68! (Some wired keyboards/mice are actually USB+PS/2 combo and work with just passive converters.)
It won't ship to Germany, so I hope someone in the US will test it.

Looks like good a solution, if someone wants wireless or is afraid of PS/2 obsolecence.


Derek_Stewart
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Re: Q68 Serial devices

Postby Derek_Stewart » Fri Feb 21, 2020 6:00 pm

Hi,

I looked at the eBay advert for the KVUSBNF unit, they will only ship outside the USA and Canada, if the purchaser has a UPS account.

This sort of limits the purchase options.

I do have a UPS account, so could import them if enough people wanted one.


Regards,

Derek

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