New FPGA cores for Mist, MCC216, MCCTV, Chameleon and Chameleon 2

[New FPGA cores for Mist, MCC216, MCCTV, Chameleon and Chameleon 2]

Good to hear it started to work. I had a problem when the PLL reconfig kicked in during the initial ROM download, thus I've added a patch to hold it during that. But it's already in the github version, so if you also integrated it, then it should be working.

[New FPGA cores for Mist, MCC216, MCCTV, Chameleon and Chameleon 2]

Many thanks! This effort started 2 years ago, I hope it'll be finished soon.

[New FPGA cores for Mist, MCC216, MCCTV, Chameleon and Chameleon 2]

I've did some tests, and I suspect it's because of the image is considered read-only (at least while I've worked on the change below, it was an issue).

Meanwhile I've finished the full "Mistification" of the core, and uploaded the results here:

https://github.com/gyurco/Atari800XL/commits/mist

Can you integrate it to your source tree please?

Global changes are almost zero (two #ifdefs in main.h only).

[New FPGA cores for Mist, MCC216, MCCTV, Chameleon and Chameleon 2]

The last one which works is 20190719.

[New FPGA cores for Mist, MCC216, MCCTV, Chameleon and Chameleon 2]

@foft: I've noticed that the latest builds (on MiST), has problems with disk writes: they always results in Error-138 (timeout), then the firmware goes crazy, F11, F12 no more work. I think the problem started somewhere around the firmware fork (firmware_legacy and firmware_exclairexl), as it works with some older versions from 2019.

[MIST vs MISTER?]

On 4/10/2020 at 5:26 AM, eightbit said:

So, fast forward to recently (last week actually) I started thinking about revisiting FPGA gaming and computing. I saw that the old MiST was at v1.4 and is still sold by Lotharek. I almost purchased it but checked on core status beforehand. Well, not much has changed. People are just no longer working on cores for it. I am not going to say all work stopped, but at least the few cores I was interested in have not been updated in a year or longer.

 

On contrast, the MiSTer project is in full swing. Every other day I check and some update has happened to a core...or a new core was introduced. Lots of activity means a brighter future in my eyes. So, I gave up on the MiST purchase idea and went for the MiSTer.

I don't know what did you check, but lot of code which end up on MiSTer still taken from MiST. It's just not promoted on that level.

[MIST vs MISTER?]

6 hours ago, ijor said:

To be completely fair, I'm not sure this is 100% accurate. The board design files, AFAIK, were never published, right? Guess this was a Lotharek requirement and perfectly understandable.

 

Yes, only board schematics and a PDF of the PCB is published, but this didn't prevent two identical clones, and one with a Cyclone IV FPGA already. Too bad not with a bigger model.

 

And to be fair, your contribution raised the accuracy of the 68000 based cores to a new level (which are not just ST and Genesis, but several arcade cores are using FX68K, too).

[MIST vs MISTER?]

I found this topic, and I felt I must write something here...

I've spent a lot of time (and it's really a lot) with MiST. I've also developed a lot of code on it. And I still like it.

MiST is already 6 (or 7?) years old. Yet still capable of many thing. MiSTer of course is more powerful. Not just the FPGA has much more space, but the ARM side is stronger. However it has an unfair advantage: For every DE10-nano purchase, Intel pays the bill. The FPGA chip itself is more expensive than the whole MiST! The HDMI license for producing this board in small quantity would be also huge. Of course, as a user, probably nobody cares. But this basically stopped custom board development, since nobody can compete with this price. The realistic price would be probably around 5-600$. Also this board is not intended to sell to end-users. If some kind of fair-trade commission would exist, they surely could sue the sellers for selling under cost price, but I'm not a legal man to discuss this.

 

But even MiST is old, and less powerful, it still has some advantage (at least what I feel as an advantage):

- Fully open source design, the whole board can be built at home (well, if you have very good soldering skills).

- Single board, USB HUB included.

- No cooling is needed, the FPGA nor the ARM are warmer than the room.

- Some cores are still better (I feel many MiSTer cores goes to a more features direction instead of accuracy - also the huge number of available resources are encouraging developers to write lousy code).

- Better SDRAM placement, the GPIO pins on the DE10-nano are not really designed for driving a fast SDRAM.

 

And for some advantages to a developer:

- No Linux, it's much more fun to hack on the firmware.

- Faster compile time of the cores.

- Simpler framework.

- No code gets rewritten just because the coding style of the original.

 

I don't want to start a war, it's just my personal opinion, and why I'm still on MiST (however a fair amount of my code are also ported to MiSTer). Maybe I like retro hardware on retro hardware

 

About the A2600: the original core from Retromaster is closely designed around the authentic TIA hardware. The lfsr counters, event handling, and so on. I've added some missing features, and now the core is almost 100% perfect on MiST. I cannot find a single glitch in games. Maybe the RIOT timer is not perfect in some circumstances. Then this code is ported to MiSTer. I wonder why the people are complaining there, don't know what went wrong. However about Rysha's A7800 core: I saw the code. The TIA there is from some university project, which is surely crap. It's not the Retromaster's TIA. I'm sure that has to be replaced. Also I don't know why that code is used. Maybe because it's Verilog, Retromaster's TIA is VHDL.