Update on the Status of 1943 for MiSTer
About 10 days ago I released 1943 for MiST, but I know most of you want the MiSTer version. However, the port didn't go as expected, why?
MiST FPGA can work well with different circuits operating inside it at different clock speeds. The MiST SDRAM chip is also relatively close to the FPGA and that makes it more reliable. It was easy to get MiST to work at 106 MHz for SDRAM access while the core itself was running at just 12MHz.
For MiSTer the situation is an FPGA that doesn't like jumping from one clock to another and requires modifying the design. Plus, the SDRAM chip sits on an addon that connects through an unbalanced header, making it rather unpredictable. So MiSTer was asking for a lower SDRAM speed access and no more than one clock.
To fix this, I have been working all this time to have a single clock at 48MHz to run the SDRAM and the game core itself. It has been a bit of a nightmare. But I finally got it working today. I still have to polish it a bit but I see the light now!
Comments (10)
Truly appreciate the extra effort to get this release out, and also for the continued updates.
Thank you for logging all these informations
was it only due to the pause screen ?
The beta version was hacked to get something working but it was very sensitive to any change. So, when I copied the latest files -that included the pause screen plus other changes- it stopped working. Anyway, I had to replace the hack for a robust design. It's just that not having it working has been quite frustrating.
Wow! I’m so thankful there are people like you out there who enjoy doing this stuff with your precious free time.
You're a wizard
Was the beta version you released earlier running at a higher SDRAM speed, or was there something else that caused it to work on Mister?
It was running at a high speed too but it was a hacked controller with a lot of timing errors. I only published it because it was a beta. For a public release I want to provide a robust core that will work for any MiSTer even without fan or heat sink.
Awesome news, thanks for your diligence and giving constant updates like CNN.
I believe in you!