The Sinclair QL Forum

martyn_hill wrote: Fri Oct 06, 2023 5:45 pm There are a number of very interesting and useful uses to put to a co-processor and, with the QIMSI's direct FIFO link back to the QL itself, we now have a viable solution (the FIFO link was always a bottleneck in my own designs for adding a co-processor to the QL...)

Many thanks Martyn. If you like to use C language for QIMSI, maybe I could upload the compiled GCC toolchain somewhere (again) and help you to get it working in a telephone session. The toolchain is quite large with 33 MB packed size, I wonder if it could be permanently hosted on dilwyn.theqlforum.com, if more people start playing with the MiniQ68 inside QIMSI.

tofro wrote: Fri Oct 06, 2023 2:23 pm My understanding is that Peter has managed to build a "68k/SMSQ/E-based Arduino", and QIMSI is just one example application for it.

Hehe yes, sort of... I just lack the time to write good docs and implement more I/O options. And Stephan probably does not want to build tens of thousands of QIMSI in order to achive a competitive price.

Great idea Peter, very useful!

Hi Peter,

thanks for the announcement. What a journey Peter, from the beginning with the first attempts to attach your Qzero to the QL Rom Port about one year ago and the uncountable ups and downs we have been faced? Just to mention one, where we had the intention to announce the QIMSI during the German Sinclair Spectrum / QL meeting this spring? Chip crisis was still a fact and we managed to get our hands on achievable 10 FPGAs for QIMSI and 10 different FPGAs for QZERO. We send all this to the assembly fab. When I got back the PCBs and open the box and recognized that they put QZERO FPGAs on the QIMSI PCB and vice versa. All our hopes turned into smoke.... And I still remember your words when I send you the Photos

Why I am writing this? First of all, it was really great fun to work with Peter on the QIMSI and make it available for the community. Beside the fact that our roles have been quite clear, Peter does the development and I do the production and testing side I learned so much about the QL and FPGAs, we would have missed a lot if we did not start the project. Thanks again Peter! On the other hand I want to emphasize that we put a lot of our spare time and our own money into this project. The QL community is quite small and we hope to fill a gap with the QIMSI to keep the community alive and together. I would be rather happy if you keep this in mind.

Thanks to Diane, Wolfgang, Martyn, Derek, Jan for your support, testing and valuable input.

I will open a thread supporting information how you get your hand on a QIMSI

Best regards,

Stephan

lliont wrote: Sat Oct 07, 2023 8:15 am Great idea Peter, very useful!

Thanks Leon! As you work on ZX8301 replacements, you remind me of a fun episode, abusing QIMSI as video interface, too.

I found that with a GoldCard or SuperGoldCard, it is possible to identify access to the QL video memory area with just one additional signal, which is DSL. As these cards only use either the internal registers or the video memory when they access the QL bus, it is possible to guess from the signal timing when such an access happens, and make QIMSI store the data. So I added a DSL wire (QIMSI has a few additional pins), video logic from the Qzero, and a little signal processing inside the QIMSI chip. And voila, QIMSI generated a perfect VGA picture. It could even switch between MODE 4 and MODE 8. Probably most crazy to implement a QL video card on the ROM port.

Fortunately, the nice VGA adaptor from Oliver, and the existence of your full ZX8301 replacement kept me from turning this craziness into an actual feature. The required RAM is probably better used for the embedded CPU. And the option of an extra wire is now used to make the QL speaker play sampled sound.

An unusual question about QIMSI:

I have two QLs. One has a QIMI inside.

Obviously, I would not deliberately try a QIMSI on that QL. But if I accidentally plugged a QIMSI into that QL (which already has QIMI) by mistake, would it cause damage?

I think I will label the QIMI QL just in case I do this by mistake eventually (knowing what I am like with hardware).

dilwyn wrote: Sat Oct 07, 2023 9:59 am An unusual question about QIMSI:

I have two QLs. One has a QIMI inside.

Obviously, I would not deliberately try a QIMSI on that QL. But if I accidentally plugged a QIMSI into that QL (which already has QIMI) by mistake, would it cause damage?

I think I will label the QIMI QL just in case I do this by mistake eventually (knowing what I am like with hardware).

You have to buy a cat to deal with the extra mice

dilwyn wrote: Sat Oct 07, 2023 9:59 am An unusual question about QIMSI:

I have two QLs. One has a QIMI inside.

Obviously, I would not deliberately try a QIMSI on that QL. But if I accidentally plugged a QIMSI into that QL (which already has QIMI) by mistake, would it cause damage?

I think I will label the QIMI QL just in case I do this by mistake eventually (knowing what I am like with hardware).

Unlikely that it will do any harm. The QIMI and the QIMSI occupy entirely different hardware adresses. There might be software collisions between the drivers as both would want to deposit the mouse position into the same place, but that won't do any lasting nastyness.

vanpeebles wrote: Sat Oct 07, 2023 10:02 am

dilwyn wrote: Sat Oct 07, 2023 9:59 am An unusual question about QIMSI:

I have two QLs. One has a QIMI inside.

Obviously, I would not deliberately try a QIMSI on that QL. But if I accidentally plugged a QIMSI into that QL (which already has QIMI) by mistake, would it cause damage?

I think I will label the QIMI QL just in case I do this by mistake eventually (knowing what I am like with hardware).

You have to buy a cat to deal with the extra mice

Only vanpeebles could come up with an answer like that

Thank you for your contribution to the community!!