Issue 8 discussions...

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Dave
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Re: Issue 8 discussions...

Postby Dave » Wed Dec 11, 2019 10:58 pm

I can wire patch that on the prototype boards under the CPU. On 4M_V5 U8 pin 36 is tied to GND. I don't know why, but the V5 layout is disconnected from the schematic, so I'll spend a bit of time trying to reconnect it so I can just import the change.

Keep everything proper.

I'll take this to email.


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Dave
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Re: Issue 8 discussions...

Postby Dave » Tue Jan 07, 2020 10:36 pm

I've been doing a bit of work on this. Progress has been made.


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Re: Issue 8 discussions...

Postby Nasta » Wed Jan 08, 2020 12:24 am

Well, running late on this side cause I had to re-install the computer, which involves putting a new OS on it and then putting the old one in a virtual machine on the first one. On the plus side, this ended up with my current 27" 2k monitor being replaced by a 40" 4k TV which I'm using as a monitor now... finally enough screen space and pixels big enough for me to actually see :)
...40" is bordering on perverse, and that's coming from nearly a lifetime working with CAD packages, where there is no monitor large enough and there is no resolution that can be too much :)


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Dave
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Re: Issue 8 discussions...

Postby Dave » Wed Jan 08, 2020 2:32 am

You'd have a cow if you had my two 43" 4K screens!

There isn't an immediate rush. Once these clean-ups are done, it'll take a couple of weeks to get and assemble the boards, and another week for one to reach you.


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Re: Issue 8 discussions...

Postby Dave » Sun Feb 02, 2020 8:49 am

Aaaand, the urge has struck me and I am back to work.

Don't get your hopes up, but I have been accomplishing things recently.


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Re: Issue 8 discussions...

Postby Pr0f » Sun Feb 02, 2020 9:07 am

:-)

it must be this time of year Dave.


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Re: Issue 8 discussions...

Postby Dave » Sun Feb 02, 2020 5:23 pm

I took on some retro projects for other machines, that are smaller and that have schematics and complete logic available. This includes a WiFi/serial/memory card for the Coleco Adam and a memory card for the VIC-20. I also built a small 68000 SBC that is NOT a QL, and have used it as a fun little test platform. On that I have got a 90s plug and play SuperIO chip to partially configure so floppy, and a couple of other devices are where I want them in the address map. It's a fun little chip. On a QL it would be useful, but it would also need software support and that's where my world falls apart!

I recently came by some 16mbit (2Mx2 SRAMs, and am looking at doing a sister design to the 4M RAM card. I understand how the decode logic works on that, but not how DRAM refresh works, and Nasta is so busy with work right now that he is really not able to spend time on it. I just want to have something complete and out there.

The other thing I have been playing with is a VDP that is hardware compatible with the QL, but has so many retro applications it's comical. Unfortunately, in one of the modes, the QL's bit order for colour info is 'non-standard' so it requires some interpretation. This requires a remap in a small eprom or flash, and a little bit of glue logic to track the flash bits, but with that enabled it will support 8 colours in mode 4, and 16 colours in mode 8.

As for Issue 8, the basic difference between Nasta and myself in direction is still there. In a way, his stance is a softer and gentler one, as he wants the system to be upgradeable. I see the Issue 8 as the end of the line for the QL, and that anything beyond that would require deep changes. So I want it to be a single integrated PCB, and Nasta wants it to have video on a daughter card. We both mean well, and we're both a bit wrong.

I'd really like to explore the Q68's video system a bit, as it is the current gold standard. Anything I can do to emulate that as far as possible will aid in getting it working with SMSQ/E or Minerva. Orinically, Minerva will be more likely to get support first.

So, that's what I've been up to and plan for the coming weeks.


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Re: Issue 8 discussions...

Postby Dave » Sun Feb 02, 2020 5:39 pm

Rambling from another thread edited out there and deposited here:

Tetroid's new Trump/SD/RTC/Minerva is a highly integrated equivalent to what SQBv4 was planned to be. The main difference is SQBv4 had four IDE ports which could take SD, CF or SATA adaptors. Everything else is comparable. However, it used four GALs instead of a larger programmable logic. I have a rule that I do not compete with products that already do the job well and are available from a current maker, so I'm simply going to let that one go - at least for now.

Currently, my interest is on doing a +D clone specifically for the Spectrum Next and playing with CPUs and SuperIO. Those will feed into whatever follows Issue 8.

As far as Issue 8 is concerned, the TX board is very much not the same thing at all - it's a cleaned up Issue 7, but retains many of the flaws of the 7. The Issue 8 completely redesigns everything, from scratch, to make a 100% compatible hardware design that is also much more flexible and useful.



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