Search found 534 matches

by dshadoff
Tue Mar 26, 2024 5:41 pm
Forum: PC Engine, TurboGrafx 16/CD
Topic: No Direct Video/scart RGB signal for Turbografx
Replies: 4
Views: 848

Re: No Direct Video/scart RGB signal for Turbografx

I'm not clear on the details, but when the HDMI Direct output was originally added, Sorgelig had posted about a particular HDMI2VGA adapter as being compatible, and that many others were not so compatible. Third-party goods are not all alike, even when based around the same core chip; retailers selling MiSTer products should be aware of compatibili...
by dshadoff
Thu Mar 21, 2024 2:03 am
Forum: Other Computer / System Cores
Topic: Coco3 Core Released
Replies: 50
Views: 49650

Re: Coco3 Core Released

shodge wrote: Tue Feb 06, 2024 2:43 am
  1. For cycle accurate 6809, changed PH2 to cpu_cycle_ena. (Improve timing of control register writes)

How did you realize that this was incorrect ? (was some software failing ?)
The 6809 is quite a popular CPU for arcades and other boards, so this change may be helpful to bring to other cores.

by dshadoff
Tue Mar 12, 2024 7:53 pm
Forum: General Discussions
Topic: Exact Latency Requirements for SRAM, Anyone Know?
Replies: 2
Views: 519

Re: Exact Latency Requirements for SRAM, Anyone Know?

Does anyone know the exact latency requirements for SRAM? I can't find it anywhere, only that it's less latency than the DDR3. The Alliance SRAM used on the 128MiB board has 3 cycle CAS at 143MHz, about 21ns; that doesn't account for row precharge, row-to-column, etc.. It's also $13 per chip, and you need 2. New HyperRAM at 250MHz has 28ns initial...
by dshadoff
Thu Feb 22, 2024 5:55 pm
Forum: Arcade Cores
Topic: Exidy Universal Game Board 2 core issues
Replies: 7
Views: 1263

Re: Exidy Universal Game Board 2 core issues

I'm pretty sure that Anton said that not all of the sounds across all of the games were implemented yet, but that it was good enough for release (so that people could play)

by dshadoff
Sat Feb 17, 2024 5:07 pm
Forum: General Discussions
Topic: Slowdown in games
Replies: 10
Views: 3431

Re: Slowdown in games

In general, slowdown on an FPGA system would be either due to “the original system also had slowdown”, or some element of the original system is not properly emulated, leading to signals not occurring at the correct time. It’s not the same as software emulation where a slow CPU can give a different outcome than a fast one. Having said that, the ide...
by dshadoff
Sat Jan 06, 2024 4:07 pm
Forum: Sega Saturn
Topic: Saturn Core Does Not Launch Games
Replies: 60
Views: 40297

Re: Saturn Core Does Not Launch Games

It might be useful for somebody (or as a group effort) to track on a spreadsheet or something, which games: work well have issues which require workaround (i.e. skip opening animation, disable controller 2, etc.) have breakage and which bios is used and tested version of the core (release date) This would probably be better for communicating known ...
by dshadoff
Thu Jan 04, 2024 2:49 pm
Forum: Other Computer / System Cores
Topic: Groovy_MiSTer Core
Replies: 259
Views: 41385

Re: Groovy_MiSTer Core

I think this is really interesting - once I was able to understand what it actually is, and how it is to be used. The MiSTer hardware is capable of lots of interesting things, even if they aren’t all self-contained videogames. I think it’s pretty cool when people create new uses which are slightly outside of what people are expecting (such as MiSTe...
by dshadoff
Mon Dec 11, 2023 4:41 pm
Forum: General Discussions
Topic: Analogue Duo?
Replies: 8
Views: 2148

Re: Analogue Duo?

There must have been an embargo; in the past 30 minutes or so, reviews have popped up from: Jeremy Parish, Metal Jesus Rocks, Game Sack, and I'm sure there are more to come.

by dshadoff
Fri Dec 01, 2023 4:20 am
Forum: Neo Geo MVS / AES / CD
Topic: Samurai Shodown RPG English Translation
Replies: 5
Views: 1991

Re: Samurai Shodown RPG English Translation

Some games (on any system) were written with the expectations that the hardware was "standard", and that timings wouldn't change appreciably. They certainly weren't tested to tun on hardware which wasn't available at the time of the release. In most cases, there is some operation happening on the CPU (or other hardware) while the CDROM is...
by dshadoff
Mon Nov 27, 2023 4:45 pm
Forum: Input Devices
Topic: Issue with USB Bus Crashing
Replies: 6
Views: 3548

Re: Issue with USB Bus Crashing

Is this the standard MiSTer USB board, or a different USB hub ? USB (prior to the 3.0 standard) was current-limited, both at the individual port and the overall hub level, to a much lower current rating. It is possible that your set of devices (especially the keyboard with LEDs) is exceeding that limit. USB 3.x introduced higher current ratings at ...
by dshadoff
Mon Nov 13, 2023 1:12 am
Forum: PC Engine, TurboGrafx 16/CD
Topic: Is the left and right channels of cd audio reversed?
Replies: 5
Views: 3856

Re: Is the left and right channels of cd audio reversed?

Thanks, but that’s not really what’s at issue, and TurboEverdrive just throws another variable in the mix. There is a test audio CD in the GitHub issue, and Artemio is going to confirm what a different discord user already told me - whether the “Left” channel on CD is being properly routed to the left speaker (and right to right) for HDMI, SPDIF, a...
by dshadoff
Sun Nov 12, 2023 8:27 pm
Forum: PC Engine, TurboGrafx 16/CD
Topic: Is the left and right channels of cd audio reversed?
Replies: 5
Views: 3856

Re: Is the left and right channels of cd audio reversed?

We have had a lively discussion on the discord server about this issue. 240P Suite only shows left/right for PSG output; CD output is a separate thing which is mixed with PSG, so it's not as straightforward as it appears. A quick test was assembled, and I did verify that the VU meters (visual display of volume) on the CD player on the System Card w...
by dshadoff
Thu Nov 09, 2023 6:39 pm
Forum: Arcade Cores
Topic: Donkey Kong: Walking Sound Hack?
Replies: 268
Views: 94068

Re: Donkey Kong: Walking Sound Hack?

Is that comment supposed to encourage some developer to work on it ?
Because that's not the vibe I'm getting...

by dshadoff
Fri Nov 03, 2023 10:17 pm
Forum: Sega Saturn
Topic: Sega Saturn Core in Development
Replies: 942
Views: 419443

Re: Sega Saturn Core in Development

Basically what you are seeing is a different kind of stress on the SDRAM. Using a 'simple' memory controller (as is included in the memtest core), you can reach one number. However, srg320's Saturn core uses a different controller, with a different access pattern. This may put different stresses on the chip which aren't demonstrated by the simple c...
by dshadoff
Sat Oct 28, 2023 5:05 pm
Forum: Sega Saturn
Topic: Sega Saturn Core in Development
Replies: 942
Views: 419443

Re: Sega Saturn Core in Development

That's not what I recall. v2.9 was made with surface-mount pin header sockets. However, there was a time when there were questions about which capacitors were to be placed in which positions on the boards for v2.5 (back around 2018, but that got straightened out). And there were some boards from some makers during that period which were found to ha...
by dshadoff
Mon Oct 23, 2023 1:16 am
Forum: Sega Saturn
Topic: Sega Saturn Core in Development
Replies: 942
Views: 419443

Re: Sega Saturn Core in Development

When you watch videos like those, you should check the date of the video, and which version the person is playing/testing. Huge leaps have been made several times in the past two weeks alone. Of course, a core of this complexity will take some time before it is difficult to find games with issues... but it is currently easy to find games that are 1...
by dshadoff
Fri Oct 20, 2023 2:14 pm
Forum: Sega Saturn
Topic: Sega Saturn Core in Development
Replies: 942
Views: 419443

Re: Sega Saturn Core in Development

Every core that is made “official” needs to reach a certain maturity (based on discussion between the author and Sorg) before it is made official. This does not mean that there would be no known bugs or that there will not be features added; merely that it is working for a lot of things. Especially tertiary features such as PhotoCD or CD+G, one sho...
by dshadoff
Tue Oct 17, 2023 4:57 pm
Forum: General Discussions
Topic: Analogue N64 Product
Replies: 32
Views: 14489

Re: Analogue N64 Product

Not just that, but depending on the tools being used, it is possible to have a different set of frequency constraints on a specific functional block than the remainder of the circuit.

by dshadoff
Mon Oct 16, 2023 6:38 pm
Forum: Display Devices
Topic: MiSTer Laggy
Replies: 64
Views: 39873

Re: MiSTer Laggy

Very nice work !
I particularly like the idea of embedding a low-level CPU for various things.
In real-world hardware, it would probably be an ARM, but I'm sure implementing 68000 was much easier.

by dshadoff
Mon Oct 16, 2023 4:09 pm
Forum: General Discussions
Topic: Analogue N64 Product
Replies: 32
Views: 14489

Re: Analogue N64 Product

They will block flashcarts? 8-) No, not intentionally - they haven't intentionally done that before. It would destroy their market. However, they have created consoles where the cartridge bus timing was off-spec causing issues for Everdrives on one of their products. Everdrive updated their product after that, but I think it had to be dealt with b...
by dshadoff
Fri Oct 13, 2023 7:08 pm
Forum: PC Engine, TurboGrafx 16/CD
Topic: Castlevania/Dracula Rondo Missing SFX?
Replies: 18
Views: 29777

Re: Castlevania/Dracula Rondo Missing SFX?

It's always preferable to play with default settings, but for some reason about a decade ago, it became popular for people to replace the music on rips with louder music, and this is also the reason why there is a "CD Audio Boost" setting on the core (note: "Off" is normal console behaviour). This will of course have an impact o...
by dshadoff
Mon Oct 09, 2023 6:51 pm
Forum: General Discussions
Topic: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?
Replies: 78
Views: 18974

Re: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?

I posted early in the thread about the definition of "cycle accurate" not meaning what most people think it does. Just to reiterate... As one digs deeper into compatibility, one finds that "cycle accurate" is measuring really only one set of variables related to compatibility. There are edge cases related to register initializat...
by dshadoff
Mon Oct 09, 2023 4:53 pm
Forum: General Discussions
Topic: Intel Preparing to Spin-off Altera
Replies: 21
Views: 6185

Re: Intel Preparing to Spin-off Altera

So all these years of back and forth… have been about the perceived definition of the word ‘subsidized’ ? If/when I have ever made a statement using the word, I have intended it to mean that Intel is providing the chips on more favorable terms than a similar-volume product, on the basis that it is a vehicle for marketing. This is a standard practic...
by dshadoff
Fri Oct 06, 2023 8:36 pm
Forum: General Discussions
Topic: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?
Replies: 78
Views: 18974

Re: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?

I suppose I should clarify, in that rhester72's response was referring to a statement: "With FPGA I don’t have to worry that maybe I will find a game with slowdown. It is guaranteed by the architecture that all games run perfectly, regardless how much they tax the original hardware." rhester72 was indeed correct to say that there are inde...
by dshadoff
Fri Oct 06, 2023 8:35 pm
Forum: General Discussions
Topic: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?
Replies: 78
Views: 18974

Re: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?

Erm...no. So much no. If a game/software you are executing on FPGA wants/requires more resources than the simulated processor, it's going to choke and slow down, just like original hardware . Metal Slug 2 on Neo-Geo is a fantastic example of this, but there are hundreds of others. FPGA has a lot going for it...this is NOT one. If a poorly-written ...
by dshadoff
Fri Oct 06, 2023 8:29 pm
Forum: General Discussions
Topic: Intel Preparing to Spin-off Altera
Replies: 21
Views: 6185

Re: Intel Preparing to Spin-off Altera

Altera (or whatever the separated entity will be called) will still need to promote their devices, so there will continue to be a Terasic relationship (as there has been since prior to Intel's purchase), and there will continue to be development boards. They will continue to make and sell FPGAs, and Intel will still own a substantial portion of the...
by dshadoff
Fri Oct 06, 2023 1:15 pm
Forum: General Discussions
Topic: Intel Preparing to Spin-off Altera
Replies: 21
Views: 6185

Re: Intel Preparing to Spin-off Altera

I doubt that Intel ever saw much opportunity beyond a perceived expanding market with high margins that they could milk. Certainly, the low end is no longer under their control, and margins are much lower than they once were in that segment. Spinning off a portion of the company is a way for them to obtain some desperately-needed cash for their oth...
by dshadoff
Sat Sep 23, 2023 1:47 am
Forum: General Discussions
Topic: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?
Replies: 78
Views: 18974

Re: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?

While it is true that everything which can be done on FPGA can also be done in software with a sufficiently-fast computer (*), I will remind people of a point I’ve made in the past: In the early days of emulation, all system operation was inferred from either documentaion (i.e. 6502 datasheets), or software-based empirical tests. There are limits t...
by dshadoff
Fri Sep 22, 2023 2:58 pm
Forum: General Discussions
Topic: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?
Replies: 78
Views: 18974

Re: The “Cycle Accurate” Conundrum and Is There a List of Cores That Are?

As one digs deeper into compatibility, one finds that "cycle accurate" is measuring really only one set of variables related to compatibility. There are edge cases related to register initialization values, and interactions between any two components inside the machine - which means that more components means exponentially larger numbers ...
by dshadoff
Thu Aug 31, 2023 4:11 am
Forum: General Discussions
Topic: CYC1000 / Handheld SNES FPGA Device?
Replies: 7
Views: 5544

Re: CYC1000 / Handheld SNES FPGA Device?

This could work for some cores, but probably not snes.
I don’t see a separate CPU on that, so lots of I/O functions would need to be implemented in a soft CPU, stealing a large number of your LE’s. Might be possible to do one of the older arcade systems though (without video scaler, etc)