Using C64 Core on MiniMig boards.

[boing4000]

Hojo_Norem wrote:
49Hz sounds a little slow.  I thought the PAL C64 refreshed at 50.12Hz?

Yep it should be at least 50Hz @ 30-31KHz but the timing settings are a bit difficult to adjust. First it was 56Hz and everything was running too fast. Perhaps I may be able to create a 2nd dcm clock generator to gain a better adjustment.

Until now also PAL and NTSC 15KHz screen is available. Currently just static but also in the future selectable via existing 15/31KHz jumper. Im working on it...

I found out that multiloader are very sensible programming stuff. Right now no scene demo is able to load the next part. It may caused by the core (source) itself but I can not reproduce that theory. If possible someone else could test the following demos on another FPGA64 porting:
- Deus Ex - Machina
- Oxyron - Natural Wonders
- Execute - Overdrive

@Belial6
I will inform me about that issue. If there are public/free ROM image available, I could implement them in the core. But first I'll have to make sure.

Thx :-)

[boing4000]

I dont know the full rights-system of emulators including rom images on the internet. But if one will share this files without permission it could cost a huge amount of money. Even if this rom copyrights are very old like the C64 one.

The idea of having some kind of flashrom to store necessary rom images is a good one! Using PIC to upload (different) rom files in the current state, will require an intelligence how to handle Amiga-kick.rom and anything-else.rom to the just uploaded core file.
Handshaking is a difficult thing to do, especially in complex (working) core files like a native C64 that dont have any clue of SPI bus system or "whats a PIC...?".

Perhaps in the future it will be possible, but it would require a lot of work and knowledge about the ported system structure. Still it is possible, like we see on Minimig Amiga Chipset and its PIC communication (floppy simmulation) :-)

[boing4000]

That could indeed be a way. The s-ram will hold its data even while hard resetting or reprogramming the FPGA.
We would use the working minimig Amiga chipset core to fill a special part of s-ram with some rom image. Then simply swap sd-card, reset the system by pgm reset button and let PIC upload the next core. If this core will look for its rom data in the same address range uploaded before, then it could actually work!

In this case no PIC reflashing will be necessary! I can try to check this out by some test-core that only read particular add.ranges filled by the "Amiga" core.
Thx for this idea :-)