Beyond Super Gold Card

[Cristian]

People just love the BBQL, it’s iconic

...and don't forget the microdrives!

[Peter]

USB is very CPU intensive, so ill suited to the 80s generation of machines without a co-processor to handle the control. To be honest this is no different than the QL's internal keyboard processor having the keyboard and serial port stuff handed to it.

It is very different, inasmuch the matrix keyboard handling is so simple that even the Spectrum could easily do it with the Z80 and no coprocessor. The IPC was not needed for this this task, a design decision untypical for the Sinclair simplicity (adding to cost, complexity, immature release and commercial flop). But even if we assume the QL IPC made sense for keyboard, that can still not be compared to adding an ARM CPU to a native 68K design.

In the QL, the IPC was a slave microcontroller, far less complex than the main CPU. A modern ARM would turn this relationship upside down - the coprocessor being the big guy in the design.

Use some dual ported RAM for data transfer and write a protocol for the 680x0 to tell it what to do and Kate's your auntie.

I won't, at least as long I do my designs just as a hobby. One reason being my QL design philosophy. The second reason, I want to spend my time on 68K not ARM. ARM Microcontrollers are simply boring for me.

[Peter]

...and don't forget the microdrives!

A valid point. Hardly ever used, if SD card is there, but nice to have for nostalgic reasons. Microdrive support would indeed distinguish such a card from the Q68, but it is very hard to achieve with minimal reward. Probably better suited to projects like Dave's Issue 8 that aim for full QL compatibility and can run a 68008 at original speed.

Mainly a software timing issue. Similar effort as getting the QLNET timings right on the Q68, but that was at least a relatively motivating goal (for Martyn who did a great job on it by the way).

[Peter]

So, an embedded ARM core or arduino handling this would not be out of keeping with a true QL, it'd merely be a peripheral interface controller.

Another idea: If you find this a nice approach, why not use PS/2 as protocol and do such an ARM controller project yourself? As a little stand-alone interface board, it would not even be QL specific and could find a wider audience as USB to PS/2 converter.

[stephen_usher]

So, an embedded ARM core or arduino handling this would not be out of keeping with a true QL, it'd merely be a peripheral interface controller.

Another idea: If you find this a nice approach, why not use PS/2 as protocol and do such an ARM controller project yourself? As a little stand-alone interface board, it would not even be QL specific and could find a wider audience as USB to PS/2 converter.

USB can do far more than just keyboards and mice, which are just slow speed serial devices anyway.

Just think being able to access USB thumb drives as "WIN_" type devices with the peripheral controller doing all the nasty filesystem conversion and file meta-data header stuff for you and the QL driver for the device acting at a higher level presenting the information in a manner that QDOS can understand.

How about USB printer access capability with the spooler running in the controller so that QDOS can fire and forget?

Of course, you could merely add a Raspberry Pi GPIO compatible header and some flash ROM on the QL expansion board so others can do that work instead of you, in the same way that the ZX Spectrum Next team are allowing the optional Raspberry Pi Zero to do things for the main system (such as taking TAP files, interpreting them and then sending the simulated tape audio into the Spectrum part to load programs). You'd probably just have to memory map the port and add latches for input/output data but that might be all that you need.

Food for thought?

[tofro]

Note the Q68 supports I2c comms. Which is definitely a "Raspberry Pi compatible header"

Connect your Raspi to that as an I2C slave, and you can do everything you mention. I don't see the need to change the hardware in any way to do what you propose.

Tobias

[stephen_usher]

Note the Q68 supports I2c comms. Which is definitely a "Raspberry Pi compatible header"

Connect your Raspi to that as an I2C slave, and you can do everything you mention. I don't see the need to change the hardware in any way to do what you propose.

Tobias

But can a Pi Zero sit as a daughter board on top in this sort of manner?

s-l300.jpg (16.74 KiB) Viewed 3294 times

[Peter]

USB can do far more than just keyboards and mice, which are just slow speed serial devices anyway.

I'm not asking for increased design complexity, while I have doubts that even the given complexity is worth the large effort.
There are many things non-QL systems can do, and I'm fully aware. Still, I'm not here to look for extra work on ARMs.

Converting USB keyboard/mouse to something simple like PS/2 can be done seperately, ARM fans are welcome to spend their own time.

Connect your Raspi to that as an I2C slave, and you can do everything you mention. I don't see the need to change the hardware in any way to do what you propose.

And interesting to find that the Raspi I2C slave mode seems to be decently supported by now. That took years.

[Peter]

What I have learned in this thread by now:

- The major reason why people want a plug-in for the QL is emotional not technical, while the Q68 "does the job" for most
- Some still actually work on the original QL keyboard
- The demand for colours seems modest for a SGC successor
- At least one person needs microdrive support even on a fast system beyond SGC

[Derek_Stewart]

Hi,

I mainly use the Q68 in 4 colour 1024x768 mode (DISP_MODE 4), which most QL software runs in this mode, that I have.

High Colour modes are not that important, the 512x384 DISP_MODE 6 is good for most applications I use. But on saying this, if the Q68 could do High Colour and High Resolution without any slow down, I would use that.

I do not use microdrives, I got rid of them when the QL had floppy disk drives, probably when Miracle
launched the Trump card.

I like the I2C interface built into the Q68, but have not had time to use it. Also I like the idea of Tofro
to use a Raspberry Pi as I2C Slave. I will have do some reading on I2C.

I am not bothered by the lack of USB interface, even if there was a USB interface who would write the drivers for all the USB devices. I doubt USB device manufacturers would write the device driver for the small QL world.

I think the main problem with the QL now is the lack economic solution for connection to a digital display, okay, there are SCART to HDMI adapters, which I have tried 5 different brands, which can not cope with the QL display. The OSSC interface maybe the best solution, but too expensive.

Maybe a better video adapter for the QL is required.