MiSTer FPGA Forum

I wouldn't discourage anyone from attempting an 80286 core but it doesn't have a huge game library. I'd like to see a list of any games that won't fit either the PCXT or the ao486 cores. It will probably be a very small list and we might find workarounds to make the games work in existing cores. Somebody mentioned The Lion King not working well wi...

I've had issues too with 15khz output from this core, I was waiting for the core to mature though before I bugged anyone about it. I guess the core is getting pretty close to that now though.

dshadoff wrote: ↑Sun Nov 13, 2022 7:40 pm - how has 40 years of time affected original parts - or has the machine been kept well-maintained ?

To me, this can be the biggest one. Do we want to recreate what a Donkey Kong board sounds like today with 40+ year old components or do we want it to sound like factory new. Is there even a difference?

I'm not a huge fan of the 286, and doing an accurate recreation would be a real pain. Actually being able to use it well depends on some undocumented features that were discovered later on. It would allow some early Windows releases to run, but versions before 3.0 don't have much software. It would probably be a low-payoff effort. It does, admitte...

Fantastic job!

All the Sound Blasters before the Sound Blaster Pro are really similar to each other, they just use different sound chips. You could upgrade from one to the other by swapping out chips at the time.

Indeed. So that's why my question is how many games from 1989 onward support Sound Blaster and CGA and will run on a machine of this core's clock speed. edit: Sound Blaster 2.0 which OP requested came out in 1991 Probably more than we think since so many games supported odd combinations of hardware. Plus what is being asked here will only take sev...

Everything overlapped because of this era being full of clones and XTs still being made into the 90s. EGA would be nice but we will run into the issue of the CPU not being fast enough or games that use 80286 or 80186 specific instructions. This core is never going to be able to run everything. There is currently no EGA implementation in FPGA so som...

Great job!!

mist-rich wrote: ↑Mon Oct 31, 2022 6:17 pm Hi all,

Am I right in saying ao486 cannot output via RGB? Presumably because RGB is not digital?

It can, but at 31khz since it's VGA.

I know that in real life there were IDE cards that could operate as either 8-bit or 16-bit but when used on an 8-bit bus only half the physical drive space was accessible. I don't know if that information helps at all.

cursedverses wrote: ↑Wed Oct 26, 2022 8:53 pm From a strictly analogue hi-fi soundpoint, does this just mean you have a negative when you require a positive, and vice versa? A soundwave is representative of a speaker's movement over time after all (one polarity pushes the speaker and the other pulls).

Yes and almost anything in the audio signal path can invert the sound.

The current core could implement a better CPU without resorting to recreating the i486 at the transistor level.

The the ST-V arcade hardware would be possible on a new platform like you are describing. Cave1k. Big advancements for the ao486 core could happen. A big increase in BRAM and onboard SRAM would be a welcome upgrade to help support these sorts of things. One day I suppose, but the de10-nano is more than sufficient for our needs for now personally. ...

arromdee wrote: ↑Fri Sep 09, 2022 4:00 pm Voodoo graphics in ao486?

No. You really need a Pentium for all those games that support Voodoo graphics.

[...] Every core that uses a Z80, for example, is using the T80 module which is a recreation not based on the original hardware. Out of curiosity, why is that? Is not the actual Zilog Z80 currently decapped and traced? A more vertical oriented implementation is going to consume less resources in the core with the trade off being that it needs to r...

Caldor wrote: ↑Wed Aug 31, 2022 12:41 pm SRAM? What is that? I am pretty sure the two modules I have are 128MB SDRAM with no SRAM on them.

Does any other cores require SRAM?

spark2k06 wrote: ↑Wed Aug 31, 2022 11:17 am In order to facilitate the port to other SRAM-only FPGA projects

UltraFP64 is "almost done" by now and he's working on a Nexys Video Artix-7 board which is around $475 today. 475 is really not that bad but this bring many questions: - Will it be easy to migrate all the cores we have from one board to the other? (this include the software but also the hardware [compatibilities with things like Jamma, R...

It probably makes sense to try to debug all those games that freeze or have errors to search for similar issues.

I've already responded to the issue, I'm sure the problem is with the UART module timings but I'm not so sure we should invest a lot of time in solving it (unless we identify a simple solution)... because, in the long run, we'll discard it when we have IDE and floppy. It still might be worthwhile to track it down in case there was ever a reason so...

A Y/C version of the core would need to be created to get those effects. CGA uses a pixel clock of nearly 21 Mhz to achieve such precise color artifacting over composite.

Hi all! I've watched yesterday a video of The 8 Bit Guy that explains how and why CGA 4 colors looked like 16 colors in composite: https://www.youtube.com/watch?v=niKblgZupOc. So today I've used the PCXT core via composite output but I didn't get the 16 colors, maybe it has to be implemented by code in the core? Yes that is something that would ne...

For composite: Is it best to use VGA to S-video, then S-video to composite adapter? Or is it ok to use VGA to component, then use an RCA Y cable to combine green and red for composite? Thanks. I believe using a simple RCA Y to combine green and red for composite will give the best result. It doesn't. It really requires some sort of luma trap to ge...

Have you looked into his suggestion of trying to integrate the floppy drive from the Atari ST into this core? I have already looked at several projects, yes, that one too. They're all proving to be a real challenge for me, unfortunately... one day we'll have some integrated, for sure, but at least for the moment they're proving to be unattainable ...

If I understood sorgelig correctly, he won't accept this core until the IDE controller works. He seemed pretty horrified by the serdrive idea. Well integrated in the Main , except that it will take up a bit more than usual, I don't see what the drawback could be, the serdrive would only be active when the core running... for other cores, it wouldn...

breiztiger wrote: ↑Thu Aug 04, 2022 7:38 pm As the Spectrum next

Or the MEGA65.

Some people like fantasy hardware, it's not my thing but I don't see why some like to complain so much about it. Let Alynna make his C128 successor.

Yeah, early 3d games lacking was the consensus even at the time. Most articles from that era that talked about 3D games focused on their potential.

Yes, it's literal. We're all worried about Sergey and hope that he's still alive.

Yeah, trying to get the PCjr BIOS going and adding cartridge support would be one thing. But trying to support every clone BIOS that ever existed is way outside the scope of this core.

Newsdee wrote: ↑Thu Jul 28, 2022 1:30 am We really need to get away from serdrive and have standard FDD/HDD support... so it will fix disk access speed and free up COM for other uses (mouse?)

It's the most important thing at this point but we need to recruit someone to do it because it seems to be beyond the abilities of everyone currently working on the core.