FX CAST Atari ST core

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Re: FX CAST Atari ST core

Postby vanfanel » Thu Oct 25, 2018 9:17 am

@Ijor: This core is incredible already. Yesterday I have been testing games and demos to no avail, and everything seems to work with no problems! Viking Child, Ishar, Ween, Amberstar, Stargoose... My favorite ST classics run flawlessly and sound exactly as I remember them! Also in love with the original Pompey Pirates cracktros, which of course run perfect on the core :D

Would it be possible that the core "respects" the scaler settings? For example, it seems to go 720p always, no matter what is specified in MiSTer.ini. And it's not applying the "vsync_adjust" setting, with causes video hiccups every few seconds because of refresh rate differences bewteen the ST implementation and the physical video mode in use.
Also, some scanlines and aspect ratio correction would be great!

What I admire most about this core is your work on the 68K and custom chipset reverse-engineering, that will give us precise 68K implementation at last! This will be a giant step in FPGA implementation of our classic computers.

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Re: FX CAST Atari ST core

Postby ijor » Thu Oct 25, 2018 1:23 pm

vanfanel wrote:Would it be possible that the core "respects" the scaler settings? For example, it seems to go 720p always, no matter what is specified in MiSTer.ini. And it's not applying the "vsync_adjust" setting, with causes video hiccups every few seconds because of refresh rate differences bewteen the ST implementation and the physical video mode in use. Also, some scanlines and aspect ratio correction would be great!


I'm currently not using VIP/Sorgelig scaler, and most of the MiSTer.ini settings are ignored. This will be solved and implemented one way or the other in a future release.

You might see video tearing and artifcats if you are running 60Hz stuff, and even more games or demos on monochrome mode that runs at 70Hz. But most games and demos run at 50Hz, and video output is sync locked at 50Hz. Make sure "Video Frequency" is configured as auto though, or the core will default to output at the "safe" 60Hz frequency disregarding the ST internal refresh rate.

If you are running at 50Hz with Video Frequency in auto, and you still see video refresh artifacts, that means that your monitor is converting the refresh rate (many do). But then I would expect this will also happens if using "vsync_adjust".
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Re: FX CAST Atari ST core

Postby vanfanel » Thu Oct 25, 2018 1:44 pm

ijor wrote:
If you are running at 50Hz with Video Frequency in auto, and you still see video refresh artifacts, that means that your monitor is converting the refresh rate (many do). But then I would expect this will also happens if using "vsync_adjust".


Yes, I am running at 50Hz, and Video Frequency is set to AUTO, and I see these hiccups every 10-15 seconds (does not look like tearing at all, but a hiccup in smooth-scrolling parts in cracktros, demos and fine-scrolling games).
On other cores, "vsync_adjust=1" corrects this, and everything is always smooth (no small hiccups, never).

My guessing here is that some monitors convert some video modes frequencies but not others. I suppose that if the video input is in the monitor native video mode then it's not converted (there's no need to it), and video latency will be smaller. That's why having support for MiSTer.ini video mode settings would be good, since users could have the core run on their monitor's native mode, which is usually among the ones listed on the .ini.

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Re: FX CAST Atari ST core

Postby Sorgelig » Thu Oct 25, 2018 1:50 pm

ijor wrote:I'm currently not using VIP/Sorgelig scaler, and most of the MiSTer.ini settings are ignored. This will be solved and implemented one way or the other in a future release.

May be you'll let me work on MiSTer API integration to the core while you can concentrate on ST code?

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Re: FX CAST Atari ST core

Postby ijor » Thu Oct 25, 2018 4:03 pm

vanfanel wrote:Yes, I am running at 50Hz, and Video Frequency is set to AUTO, and I see these hiccups every 10-15 seconds (does not look like tearing at all, but a hiccup in smooth-scrolling parts in cracktros, demos and fine-scrolling games).

My guessing here is that some monitors convert some video modes frequencies but not others. I suppose that if the video input is in the monitor native video mode then it's not converted (there's no need to it), and video latency will be smaller.


It is possible that some monitors change the refresh rate, but only when its own scaler is involved, yes.

Sorgelig wrote:May be you'll let me work on MiSTer API integration to the core while you can concentrate on ST code?


May be :) Although I did have my reasons that we can talk about in some other thread.

I do will like to say something here. The work Sorgelig did in that regard is amazing and impressive. There is a lot of stuff behind the scenes that most people, even core developers probably don't know. E.g., I had no idea you made your own adaption of the HPS TCL interface.
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Re: FX CAST Atari ST core

Postby breiztiger » Thu Oct 25, 2018 5:05 pm

hi

just tested with hdmi_audio_96k=1 but no more sound on hdmi output

other core like genesis work like a charm

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Re: FX CAST Atari ST core

Postby JimDrew » Fri Oct 26, 2018 5:37 am

Ijor, I was thinking about the image size generated by SCP with it's default settings. I could actually cut the image size in half. There is an option to use any number of bits for storing the flux data. By default, the bitcells entries are stored as 16 bits (word) wide. I could make an option to create image files with the 8 bit storage option, and then use a multiplier value in a couple of the unused flag bits. SCP does a 25ns capture, but I have done some experimenting with CopyLock and some other timed protections and found that I could make 100ns bitcells and every copy-protection still seems to work. This would reduce the max bitcell value by 4, making it fit easily into an 8 bit value. So, if it's helpful I can implement the multiplier bits into the image format. I already have an option in the software for doing this (uncheck "preservation), so it's a simple change to define some extra bits. I made this option awhile ago because it dramatically reduces the image file size to less than 10% of it's actual size when using .7zip compression. STeeM and other emulators support using SCP image files in a compressed form to reduce the amount of required disk space.
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Re: FX CAST Atari ST core

Postby OzOnE » Fri Oct 26, 2018 7:22 am

@ijor - Thanks for your reply.

That's some fantastic work, particularly on the 68000, as it's obviously a very iconic and widespread CPU, especially on arcade boards.

The same MFP chip is used in the classic Mac and SGI Indy as well, IIRC? Although I could be remembering that wrong.

I've seen some of the videos of FX CAST by bbond and others, and it looks great. ;)

I'm very glad to hear your core is written in Verilog / SystemVerilog as well. I find VHDL a bit harder to read and visualize.

I haven't yet made the change to SystemVerilog and using the "logic" keyword yet, but I guess it makes sense to.

Regards, OzOnE / ElectronAsh.

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Re: FX CAST Atari ST core

Postby ijor » Sat Oct 27, 2018 1:15 pm

OzOnE wrote:The same MFP chip is used in the classic Mac and SGI Indy as well, IIRC? Although I could be remembering that wrong.
I've seen some of the videos of FX CAST by bbond and others, and it looks great. ;)
I'm very glad to hear your core is written in Verilog / SystemVerilog as well. I find VHDL a bit harder to read and visualize.
I haven't yet made the change to SystemVerilog and using the "logic" keyword yet, but I guess it makes sense to.


Yes, early MACs and SGI were based on the 68K. I'm glad you liked the videos. I like your videos a lot! :)

SystemVerilog is just an extension to Verilog. I'm not using the most advanced and fancy SV features. Should be easy to follow. Being a very lazy typist, I hate the verbosity of VHDL myself! :)
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Re: FX CAST Atari ST core

Postby ijor » Sat Oct 27, 2018 2:48 pm

JimDrew wrote:Ijor, I was thinking about the image size generated by SCP with it's default settings. I could actually cut the image size in half. There is an option to use any number of bits for storing the flux data. By default, the bitcells entries are stored as 16 bits (word) wide. I could make an option to create image files with the 8 bit storage option, and then use a multiplier value in a couple of the unused flag bits. SCP does a 25ns capture, but I have done some experimenting with CopyLock and some other timed protections and found that I could make 100ns bitcells and every copy-protection still seems to work. This would reduce the max bitcell value by 4, making it fit easily into an 8 bit value. So, if it's helpful I can implement the multiplier bits into the image format. I already have an option in the software for doing this (uncheck "preservation), so it's a simple change to define some extra bits. I made this option awhile ago because it dramatically reduces the image file size to less than 10% of it's actual size when using .7zip compression. STeeM and other emulators support using SCP image files in a compressed form to reduce the amount of required disk space.


There are definitely some goods ideas here. And some of this is more or less what I am doing in my core while pre processing the images. Let's open another thread and exchange some ideas.
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Re: FX CAST Atari ST core

Postby thgill » Sat Oct 27, 2018 6:00 pm

I just published a video on FX CAST. Instead of gameplay, I went with demoscene productions.

https://youtu.be/0KeCrWIQVTY
Like retro computers, game consoles and other obsolete junk? Check out Todd's Nerd Cave on YouTube

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Re: FX CAST Atari ST core

Postby JimDrew » Sat Oct 27, 2018 6:28 pm

ijor wrote:There are definitely some goods ideas here. And some of this is more or less what I am doing in my core while pre processing the images. Let's open another thread and exchange some ideas.


Done! viewtopic.php?f=102&t=34598

I have also updated the .scp image file spec and have posted it on the downloads page:

http://www.cbmstuff.com/downloads.htm
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Re: FX CAST Atari ST core

Postby Kolchak » Sun Oct 28, 2018 1:11 pm

Hello,

I would like to thank you Ijor for the Fx Cast core, great work, I've been waiting for a ST Core as I owned one Atari STe some time ago :)

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Re: FX CAST Atari ST core

Postby BBond007 » Mon Oct 29, 2018 1:21 am

ijor wrote:I didn't consider supporting MIDI so far. Using an USB device is of course, possible, but quite complicated. It would need a special driver and/or a server program on the Linux side. It would be much easier if somebody would make a MIDI extension board.


Ijor,

I have re-compiled the kernel to support USB MIDI devices and have written such a server program which I have demonstrated working with the Minimig core (viewtopic.php?f=117&t=34599)

People are asking if it will work with other cores, specifically the Atari ST and ao486.

Do you think you could include an option for the Atari ST MIDI port to map to a device (such as /dev/ttyS1) which is accessible in the MiSTer Linux?

Thanks :)

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Re: FX CAST Atari ST core

Postby yarko » Mon Oct 29, 2018 7:46 am

For me personally, the most expected feature is now the ability to write to a floppy disk image.

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Re: FX CAST Atari ST core

Postby ijor » Tue Oct 30, 2018 2:31 am

thgill wrote:I just published a video on FX CAST. Instead of gameplay, I went with demoscene productions. https://youtu.be/0KeCrWIQVTY


Thank you. Great video!

BBond007 wrote:Do you think you could include an option for the Atari ST MIDI port to map to a device (such as /dev/ttyS1) which is accessible in the MiSTer Linux?


I'm not a MIDI expert, but I'm not sure this is the most suitable method for the ST, I would need to look into this. The problem is that the ST, contrary to other computers, has MIDI built-in. Then most ST MIDI software expects a very specific hardware with very precise predictable timing. As long as we implement MIDI at the FPGA side, everything is exactly like the original implementation, so it should work seamlessly. Not sure how things will behave when working over a software server, timing will probably be altered.

I'm currently out of home. I'll look into this in a few days.
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Re: FX CAST Atari ST core

Postby matt » Thu Nov 01, 2018 12:38 am

Just wanted to wish congrats on this awesome work. Bravo!

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Re: FX CAST Atari ST core

Postby SmokeMonster » Fri Nov 02, 2018 5:45 am

I posted a video about FX CAST last week: https://www.youtube.com/watch?v=VQiDpjVdtb4

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Re: FX CAST Atari ST core

Postby funkychimp » Fri Nov 02, 2018 10:08 am

Hi gents,

Can someone please help me.

I have placed Atari St core on the root on my SD. I can load it and open the F12 options etc but whne I try and load a .st file nothing happens. I just get a black screen with a white border.

Do I have to place any additional bios files etc. in the SD root?

Any help would be most appreciated.

Kind regards

funkychimp

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Re: FX CAST Atari ST core

Postby ijor » Fri Nov 02, 2018 1:53 pm

funkychimp wrote:I have placed Atari St core on the root on my SD. I can load it and open the F12 options etc but whne I try and load a .st file nothing happens. I just get a black screen with a white border.
Do I have to place any additional bios files etc. in the SD root?


No BIOS/TOS rom files are needed for this release.

Do you have an SDRAM board, don't you? Other cores work fine?
Did you try different ST images?
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Re: FX CAST Atari ST core

Postby ijor » Fri Nov 02, 2018 1:53 pm

SmokeMonster wrote:I posted a video about FX CAST last week: https://www.youtube.com/watch?v=VQiDpjVdtb4


Thanks a lot! :)
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Re: FX CAST Atari ST core

Postby funkychimp » Fri Nov 02, 2018 3:49 pm

Hi ijor,

Firstly, Thank you for all the hard work that has gone into this core! amazing stuff!

Yes, I am using the the low profile 1.1 SDRAM board.

I decided to unplug the SDRAM and reseat and the core has suddenly started to work. One quirk though. I have no sound using the core.

Any ideas?

Thanks

funkychimp

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Re: FX CAST Atari ST core

Postby cacophony » Fri Nov 02, 2018 5:40 pm

Any update on when you think the source code is likely to be released?

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Re: FX CAST Atari ST core

Postby ijor » Fri Nov 02, 2018 8:53 pm

funkychimp wrote:I decided to unplug the SDRAM and reseat and the core has suddenly started to work. One quirk though. I have no sound using the core. Any ideas?


A few people reported the same problem. I need to investigate the cause.

In the meantime, some of them found the following workaround. Run a different core, make sure you get sound on your monitor. Then switch and run the ST core. That's just a temporary workaround, and I can't guarantee it will work for you.

cacophony wrote:Any update on when you think the source code is likely to be released?


I just returned from a trip and sent the source of the 68K core to a couple of developers. That source will be released to the public shortly. The source for the ST core will be released later.
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Re: FX CAST Atari ST core

Postby ijor » Tue Nov 06, 2018 2:04 pm

funkychimp wrote:I have no sound using the core.


I think I found and I am fixing the issue that some people had no sound. The fix would be released shortly.
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