QLUB Adapter - Initial Release...

[vanpeebles]

Hi!

I have vanpeebles bugging me to support this in sQLux, is there a guide of what needs done?

Yes, he's a bit like that, isn't he

I saw that!!

[martyn_hill]

Hi Chr$!

What equivalent PNP bi-polar high-speed switching transistor is suitable instead of a ZTX-510? I'm a noob looking at datasheets and none of the PNP transistors I can find are quite the same. ZTX-510 seems to be a tricky one to find.

I typically use an online resource such as the following to find substitute transistors:
https://alltransistors.com/crsearch.php ... caps=TO226

In this application, a lower 'transition frequency' would suffice, as long as the maximum voltage and power dissipation specs are as good or higher than the 510. The ZTX-550 for example.

The gain (hfe) of any substitute is equally non-critical here as we're driving the transistor in its saturated mode and not trying to drive a lot of current - the NET is only expected to source around 24mA, and with the 47ohm current limiting series resistor, even a short (e.g. if you insert or remove the Jack plug while the line is being driven) would still only require the transistor to source a little over 100mA of (collector) current in to Gnd.

In short, the criteria for any substitute is pretty loose...

All that said, I didn't have too much trouble sourcing the ZTX-510 itself when I last tried, but that was a few months ago...

[martyn_hill]

I saw that!!

Couldn't resist - sorry, Pete

[vanpeebles]

Hehe, I can see real potential in some kind of mini file server as a means of providing base QL users a way to run files without having floppy drives etc. I’m currently thinning out my QL collection to equip my friends with QLs for the first time, but straight away I run into the usual problem of expansions etc. Floppies are long in the tooth now for people who don’t have any.

[RalfR]

ZTX-510 is discontinued from "Diodes Incorporated".

ztx510-1165219.pdf

(75.04 KiB) Downloaded 230 times

[Peter]

What equivalent PNP bi-polar high-speed switching transistor is suitable instead of a ZTX-510? I'm a noob looking at datasheets and none of the PNP transistors I can find are quite the same. ZTX-510 seems to be a tricky one to find.

It is not necessary to use a bipolar transistor. If I had to design a board for Martyn, I would use a suitable P-channel MOSFET like the IRLML2244TRPBF and abandon the 1K, 3.9K and 10 K resistors altogther. If it has to be a TO-92 case, the less efficient TP0606 MOSFET should also do that job.

Edit: To be precise, at least the 1K resistor must be removed when using a MOSFET, and left open. Also removing the 3.9K and 10K resitors is optional, those would be replaced by a wire connection.

[Chr$]

Thanks Martyn/Peter.

I nabbed 3x Teensy++ 2.0 quite cheaply from a seller in Spain (for his last one he put the price up massively - or an algorithm did).

And I've just been able to work out how to program it and after a bit of trial and error yesterday and this evening, that all seems to have gone fine. Quite chuffed about that. Now to making the circuit.

[Pr0f]

What equivalent PNP bi-polar high-speed switching transistor is suitable instead of a ZTX-510? I'm a noob looking at datasheets and none of the PNP transistors I can find are quite the same. ZTX-510 seems to be a tricky one to find.

BC559 works on a standard QL, I suspect any good PNP switching transistor - the frequencies are not huge, nor are the currents - you want to find low VCE saturation numbers, good HFE (DC gain) in the spec sheet of any candidate for replacement.

[martyn_hill]

Hi again everyone!

For those of you preparing to build the QLUB Adapter, a heads-up

After some troubleshooting Danielle's build, we discovered that the timing of the network packets sent by the microcontroller was all screwed.

We eliminated a number of possible causes - his hardware build was fine and we couldn't initially find anything different between (my) working adapter and his non-working unit.

Until, that is, we compared versions of the Arduino IDE and the 'Teensyduino' libraries - both of which have long since revved in versions since I downloaded them back in 2017...

Seems that something in either the compiler tool-chain or the later Teensyduino libraries has changed and the current QLUB firmware (v2.1f) will need revision to accommodate those changes. I had already in mind a rewrite of the firmware and will do so against the latest available IDE/Teensyduino libraries - but not for a couple of weekends.

In the meantime, should you wish to proceed with your QLUB build, you have two options:

a) Find and download the legacy Arduino IDE v1.8.0 (still available from Arduino) AND the legacy Teensyduino installer v1.35 - which I couldn't find online, but I have a copy on my harddrive... You can then just use the existing firmware source and compile/flash the Teensy board as per the instructions. OR...

b) I have the raw HEX code of the firmware as compiled with the older tool-chain which you can directly flash to the Teensy. Read-up the Arduino docs for how to directly flash with the HEX code - its pretty straightforward

I'm not sure whether I can post the legacy Teensyduino Installer here, so perhaps option b) is best. With that in mind, I attach the raw HEX matching version v2.1f of the firmware.

QLAN-USB_v21f.ino_IDE180_TDv135.zip

(15.45 KiB) Downloaded 264 times

Thanks to Danielle for both being the first early-adopter and also for sparing me 2 hours of his precious weekend to troubleshoot together!

Happy Monday

[M68008]

b) I have the raw HEX code of the firmware as compiled with the older tool-chain which you can directly flash to the Teensy.

Thank you Martyn, the adapter started working well after I uploaded this version of the firmware!

There was a change in the Teensyduino library which might be the cause of the different timings, I sent you a PM with the details.

After a SBASIC->SuperBASIC conversion of the emulator-side file-transfer program, it also runs on a Sinclair ROM in Q-emuLator.