MIST C64 core

[farvardin]

finally a C64 core that works for me! Great job, thank you.

The latest one I could use was 140707 (r292), but no sound / music at all, the other ones, from 140708 (r294) to the one before the 150716 release only display a black screen so I couldn't do anything with them.

The new version 150716 (r1209) works and there is sound (but no filter emulation, or not all of them, it's probably expected).

However, there is a little problem with the display (it was the same with r292), in PAL version at random the screen is like flickering i.e. it goes completely black (no OSD, nothing) for 1 second, then turns on again for 1 second, or 2 or 4 seconds (at random).
In NTSC it's more stable, but it can be on for 10 or 20 seconds, then black for 1 or 2 seconds.

[Paradroyd]

..However, there is a little problem with the display (it was the same with r292), in PAL version at random the screen is like flickering i.e. it goes completely black (no OSD, nothing) for 1 second, then turns on again for 1 second, or 2 or 4 seconds (at random).
In NTSC it's more stable, but it can be on for 10 or 20 seconds, then black for 1 or 2 seconds.

It is exactly the same way for me, but only on my flat panel monitors. On the CRT it is absolutely stable. I have an active VGA splitter that feeds the signal simultaneously to a CRT and a Dell flat monitor. The CRT is stable the whole time while the flat monitor is seemingly randomly cutting out and coming back. The c64 core is the only one of all of them that behaves this way. It does the same thing in both PAL and NTSC.

The 1541 support is a nice addition though.

[farvardin]

yes, I didn't develop further, but I only have a flat LCD monitor (LG brand flatron L1750B), and it's also only the C64 core that does this on this monitor, other core have a stable display.

[Newsdee]

In my experience, the c64 core always had slightly different sync timings than other cores, and not all displays are able to cope. Using an upscaler should fix it.

[remowilliams]

Yeah, I wish the 'scandoubler_disable' was a core specific setting because of the need to use an upscaler with this core.

[Newsdee]

It's not related to that, you need an upscaler to stabilize the image regardless of whether you are running 31khz or 15khz. The problem is modern LCD can only handle certain ranges of sync signals compared to old CRTs.

(source: I had horrible sync issues with an MVS board long ago, tried all kinds of stuff, turned out to be the power supply that wasn't super stable...)

[MasterOfGizmo]

The c64 core has its origins on the C-One which had a fixed pixel clock of 33.8Mhz. The whole c64 core uses this as its main clock and includes some complex mechanism to make the c64 run at roughly the original speed. I assume the various video problems arrive from that.

I've built a core that instead uses a simple scan doubler and the whole c64 is clocked at exactly 32 times the cpu clock. This currently only works correctly for PAL video modes. But i am working on that ...

[Paradroyd]

The c64 core has its origins on the C-One which had a fixed pixel clock of 33.8Mhz. The whole c64 core uses this as its main clock and includes some complex mechanism to make the c64 run at roughly the original speed. I assume the various video problems arrive from that.

I've built a core that instead uses a simple scan doubler and the whole c64 is clocked at exactly 32 times the cpu clock. This currently only works correctly for PAL video modes. But i am working on that ...

Very cool. Looking forward to it!

[NML32]

If I buy the Jiffy Dos ROMs would this core recognize them?

[obiwanken]

Last core (r1216) works perfect with my monitor (PAL). Thanks for your job.

Now add cartridge and REU support and the core will be great.

[remowilliams]

But i am working on that ...

Yay, I can see the C64 on my monitor now - thank you!

If I buy the Jiffy Dos ROMs would this core recognize them?

Not with the compiled core for sure, there's nowhere to place the C64 and 1541 Jiffy roms.

[vebxenon]

Just a question.... https://code.google.com/p/mist-board/so ... 253Dclosed Where I can download the firmware_150715_r1207 required on https://code.google.com/p/mist-board/so ... readme.txt for this core?

Regards,

Salva

[Paradroyd]

Just a question.... https://code.google.com/p/mist-board/so ... 253Dclosed Where I can download the firmware_150715_r1207 required on https://code.google.com/p/mist-board/so ... readme.txt for this core?

Regards,

Salva

It's at the bottom of the page, here.

Finally got around to trying this latest version of the core. awesome work! It seems absolutely stable on monitors it never worked on before!

- PD

[vebxenon]

Thanks very much!

[farvardin]

Thank you Till, with this new C64 core, it works perfectly for me on my LCD monitor, in PAL mode!

[vebxenon]

Core works better than ever But I've been unable to play The Simpsons Arcade and Street Fighter II. Have you tested them? Now I'm playing Bionic Commando (European version), what a great music ^_^

Regards

Salva

[Alessio]

This core is brilliant! Very stable picture on my LG monitor (M227WDP) and realistic 1541 loading times for D64 disk files. Was a bit puzzled it did not work at first, but then realized I needed to update the MiST firmware before using the new core. Thank you!

[vebxenon]

Is there any keyboard map of this core?

Regards,

Salva

[Hawk78]

Hi, sorry for asking this, but how ca i load .D64 files? On the OSD menu i can only select .prg files ?!

[Newsdee]

Are you using the latest core file and upgraded to the latest firmware?

[iceman]

Hawk78 There is an option to mount *.D64 in the OSD, at least in the latest core.

[Hawk78]

Aaah, I think I found my mistake. I took the "firmware.upg" form the google trunk dated on Jul 11,2015 (r1203). I didn't see the latest version on the next page (r1207). Thank you all for help!

[MasterOfGizmo]

The stuff on google is outdated anyway. The new home is github and the latest Firmware is at https://github.com/mist-devel/mist-bina ... r/firmware

[Newsdee]

If we can still edit the google page, we should delete everything with a link to the new one?

Also I find the github wiki a bit "hidden" (longer url, more obscure) so we might want to make a MiST page somewhere else. We could store the html source in Git so as to not be vulnerable to hosting issues (i.e we make it easy to roll out mirrors).

[farvardin]

we might want to make a MiST page somewhere else

Maybe a direct link to the wiki from http://www.harbaum.org/till/mist/index.shtml