Search found 2634 matches

by ijor
Tue Oct 23, 2018 10:25 am
Forum: MiSTer
Topic: 680x0 cores
Replies: 9
Views: 62

680x0 cores

It runs at 28MHz in my old spartan3e no problem. Doesn't seem too much. My own cycle accurate core can reach close to 40MHz, and I didn't try too much optimization because that's much more than what I need for the ST core. I also expect it could get much higher if I would be ready to sacrifice some...
by ijor
Tue Oct 23, 2018 9:51 am
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

Re: FX CAST Atari ST core

I moved the posts not specific to this core, but more related to generic 680x0 cores to a separate thread: viewtopic.php?f=117&t=34568
by ijor
Tue Oct 23, 2018 9:44 am
Forum: MiSTer
Topic: 680x0 cores
Replies: 9
Views: 62

680x0 cores

This thread is a split from this other thread: viewtopic.php?f=117&t=34555
by ijor
Tue Oct 23, 2018 9:17 am
Forum: MiSTer
Topic: If you want to donate to MiSTer project.
Replies: 103
Views: 14557

Re: If you want to donate to MiSTer project.

Use Digikey- 860 units on stock about an hour ago. I know, and Amazon will probably refill its own stock soon, if it didn't already. My point is just that they seem to be selling quite fast ... I don’t expect that Terrasic is earning much. Most likely it’s the other way around - Intel is doing nega...
by ijor
Tue Oct 23, 2018 9:12 am
Forum: MiSTer
Topic: Scaler
Replies: 7
Views: 143

Re: Scaler

Triple buffer will add 1 frame of lag. V-synced double buffer is a better solution (unless there's something I'm missing here). I agree. If you are "vsynced" you shouldn't need triple frame buffer. You actually don't need double buffer either if you can "sync" the frame buffer c...
by ijor
Tue Oct 23, 2018 9:06 am
Forum: MiST
Topic: Genesis / Megadrive core ported to MiST
Replies: 607
Views: 62615

Re: Genesis / Megadrive core ported to MiST

I like to call it "hardware re-implementation". In the end you actually wire something up. But these are pretty tiny wires inside a chip and you connect them using small switches instead of solder. But physically the difference is pretty small. But there are certain things you should do d...
by ijor
Tue Oct 23, 2018 8:33 am
Forum: MiSTer
Topic: If you want to donate to MiSTer project.
Replies: 103
Views: 14557

Re: If you want to donate to MiSTer project.

You know ... I was going to order a second DE-10 Nano board. I had one on my Amazon watch list ... During the weekend, stock was rapidly decreasing and currently it's out of stock! ... Wondering how many board Terasic sells because of MiSTer. Sorgelig might deserve to share some of the revenues! :)
by ijor
Tue Oct 23, 2018 8:27 am
Forum: MiSTer
Topic: 680x0 cores
Replies: 9
Views: 62

Re: FX CAST Atari ST core

I've finished adding the missing instructions to my m68k (tg68k) variant. What's the max speed of tg68K? The ideal combination would be to include two cores, one plain 68000 cycle accurate. And a non cycle accurate faster core. I was (still am) considering the idea for my ST core. You obviously don...
by ijor
Tue Oct 23, 2018 8:23 am
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

Re: FX CAST Atari ST core

However, with my setup I cannot test the core because I do not get a video signal. I am using MISTer's HDMI out to connect it to DVI in of my 1280x1024 LCD monitor (dvi_mode=1 and video_mode=4 in MISTer.ini) with beautiful image quality in all tested cores. Will you look into the video out issue? S...
by ijor
Tue Oct 23, 2018 12:47 am
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

Re: FX CAST Atari ST core

Is it 68000 or 68010/20/30? Bare 68000 only. You probably need almost completely separated cores for the other processors, if you want cycle accuracy. There is probably not much in common between the 68030 (or even the 68020 for that matter) and the 68000 at the gate level. The 68010 is very close ...
by ijor
Tue Oct 23, 2018 12:37 am
Forum: MiST
Topic: Genesis / Megadrive core ported to MiST
Replies: 607
Views: 62615

Re: Genesis / Megadrive core ported to MiST

I'm sure you've heard it already but let me stress it once more. This is not emulation. We are making a hardware clone without using a CPU to simulate via software the original chip behaviour. I don't want to hijack the thread, but as much as I love FPGA stuff (and I'm a core developer myself), the...
by ijor
Tue Oct 23, 2018 12:33 am
Forum: MiST
Topic: Genesis / Megadrive core ported to MiST
Replies: 607
Views: 62615

Re: Genesis / Megadrive core ported to MiST

This game masks VDP interrupts at the 68k side (SR register: 0x270..., AFAIK the second nibble is the IPL level mask). The VDP generates the interrupts, but since the 68k doesn't ack them, they remain pending. After a while, a MOVE $2000,SR happens. In the Exodus emulator, it immediately fires the ...
by ijor
Tue Oct 23, 2018 12:20 am
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

Re: FX CAST Atari ST core

Are you planning on releasing the source code for the 68k so that other projects can benefit ? I do, but it won't be today. I'd like to wait a few days, just in case the public release exposes any possible bugs in the 68K core. I also need to think and decide which open source license to use. I'm n...
by ijor
Tue Oct 23, 2018 12:07 am
Forum: MiSTer
Topic: Atari ST core. Seeking beta testers
Replies: 21
Views: 2182

Re: Atari ST core. Seeking beta testers

hlide wrote:Arf, only idiots will want to kill you. Well, they do exist - I mean idiots - because, killers, I don't know. Anyway, don't take my joke seriously. :cheers:


Don't worry. I know you were joking :)
by ijor
Mon Oct 22, 2018 3:49 pm
Forum: News & Announcements
Topic: FX CAST cycle accurate Atari ST FPGA core
Replies: 2
Views: 849

Re: FX CAST cycle accurate Atari ST FPGA core

This thread is locked. Please follow up here: viewtopic.php?f=117&t=34555
by ijor
Mon Oct 22, 2018 3:47 pm
Forum: MiSTer
Topic: Atari ST core. Seeking beta testers
Replies: 21
Views: 2182

Re: Atari ST core. Seeking beta testers

As you can see, I finally made a public release. Honestly, I wanted to complete a few more features before going public. Especially when many missing features are mostly implemented already. What is missing in most cases is the user selection and the interface with the ARM side. But considering ther...
by ijor
Mon Oct 22, 2018 3:14 pm
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

Re: FX CAST Atari ST core

Out of curiosity - did you use the designs recently uncovered here: http://www.chzsoft.de/asic-web/ in order to replicate cycle perfect chips? Not really. I made my own reverse engineering that included chips decap long before. Also, unfortunately, the archive includes schematics for a single chip ...
by ijor
Mon Oct 22, 2018 3:11 pm
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

Re: FX CAST Atari ST core

Amazing! Is there any chance to get this core on the MIST as well? A MIST version is planned. Support for copy protected images might not fit and probably would have to be dropped. The remaining main issue is ram storage for TOS. On MiSTer, I am beling lazy and storing TOS on internal FPGA RAM. Tha...
by ijor
Mon Oct 22, 2018 3:04 pm
Forum: News & Announcements
Topic: FX CAST cycle accurate Atari ST FPGA core
Replies: 2
Views: 849

Re: FX CAST cycle accurate Atari ST FPGA core

FX CAST ATARI ST core for MiSTer platform Copyright (c) 2018 by Jorge Cwik Public beta release Cycle accurate Atari ST core. The core features a cycle accurate 68000 CPU and cycle accurate chipset, including cycle accurate FDC that can load and run low level copy protected disk images. This is a pr...
by ijor
Mon Oct 22, 2018 11:59 am
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 22
Views: 1073

FX CAST Atari ST core

Announcement: viewtopic.php?f=28&t=34554

Please comment and ask questions here.
by ijor
Mon Oct 22, 2018 11:55 am
Forum: News & Announcements
Topic: FX CAST cycle accurate Atari ST FPGA core
Replies: 2
Views: 849

FX CAST cycle accurate Atari ST FPGA core

FX CAST is a cycle accurate Atari ST core. The core features a cycle accurate 68000 CPU and cycle accurate chipset , including cycle accurate FDC that can load and run low level copy protected disk images. Audio Sculpture original copy protected SCP image: AudioSculp.jpg Closure demo by Troed (SYNC...
by ijor
Thu Oct 18, 2018 7:15 pm
Forum: MiSTer
Topic: Atari ST core. Seeking beta testers
Replies: 21
Views: 2182

Re: Atari ST core. Seeking beta testers

Well, you can make a testament where it is specified the source must be published if you die. Just kidding. "Are you insane? Some idiots will kill me to get the source!". Ah, you think so? Of course that all my sources are on my will ... encrypted ... with strong encryption ... and nobody...
by ijor
Tue Oct 16, 2018 3:35 pm
Forum: Floppy Disk Preservation
Topic: Atari ST Protection Techniques Special Edition
Replies: 23
Views: 758

Re: Atari ST Protection Techniques Special Edition

Zippy wrote:I'd never heard of that protection on Boulder dash construction kit, I only got my ST in '88 so I guess that was a bit before my time and I definitely never saw an original of it. Would love to see a pic of the modified disk or a link to the old thread if it's still around.
by ijor
Tue Oct 16, 2018 1:36 pm
Forum: Floppy Disk Preservation
Topic: Atari ST Protection Techniques Special Edition
Replies: 23
Views: 758

Re: Atari ST Protection Techniques Special Edition

I don't have much time to analyze this right now. But yes, according to the protection check this would mean that the disk has (or at least that the protection expects) a physical alteration of the disk surface. This is not exactly a laser burnt. A laser burnt is very precise and it could be located...
by ijor
Tue Oct 16, 2018 12:26 pm
Forum: The Atari 8bit corner
Topic: Dumping the ROM from a XEGS?
Replies: 3
Views: 220

Re: Dumping the ROM from a XEGS?

Note that Atariage is a forum more specialized in the 8-bit. You will probably get more help there. Having said that ...

This is not an EPROM. It is a masked ROM with a different pinout. Most EPROM burners can't read masked ROMs. You might need to build a special adapter.

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