The 7800GD (New 7800 Flash Cartridge?)

[+DrVenkman]

1 hour ago, Trebor said:

Check out some of the latest developments for it...

Neat. Though I bought a Sega Light Phaser and built myself an adapter a couple years go that, ugly as it is, works great.  

 

[SparkTR]

Will the AV out work on a 7800 that has the S Video mod installed?

[SainT]

38 minutes ago, SparkTR said:

Will the AV out work on a 7800 that has the S Video mod installed?

Yes, it's entirely separate from the console. The video out from the console can even be broken as long as the Maria chip is functioning correctly and you'll get a perfect RGB picture.

[SparkTR]

1 hour ago, SainT said:

Yes, it's entirely separate from the console. The video out from the console can even be broken as long as the Maria chip is functioning correctly and you'll get a perfect RGB picture.

Perfect! Thanks!

[Mayhem]

5 hours ago, SainT said:

Yes, it's entirely separate from the console. The video out from the console can even be broken as long as the Maria chip is functioning correctly and you'll get a perfect RGB picture.

I've got an RF PAL 7800 and an S-video modded NTSC 7800 here if you're looking for someone in the UK to help test the cart

(well this method worked when helping you test the NGPC cart you did!)

[SainT]

On 3/30/2023 at 2:37 PM, Mayhem said:

I've got an RF PAL 7800 and an S-video modded NTSC 7800 here if you're looking for someone in the UK to help test the cart

(well this method worked when helping you test the NGPC cart you did!)

Indeed, I remember the NeoPocket testing! That was a while ago.

 

I think I'm sorted for testers now, but will give you a shout if I need more.

[killersquirel]

The RGB out is really exciting.  I know the answer to my question is probably no, but I will ask it anyway.  Does the cartridge in Atari 2600 mode run the homebrew games that require the Harmony to run?  It would be really awesome to play the new Zoo Keeper, Qyx, Mappy, Ladybug Arcade, etc on the RGB output.  If it can not run those games, is that something that can be done in the future?

[SainT]

5 minutes ago, killersquirel said:

The RGB out is really exciting.  I know the answer to my question is probably no, but I will ask it anyway.  Does the cartridge in Atari 2600 mode run the homebrew games that require the Harmony to run?  It would be really awesome to play the new Zoo Keeper, Qyx, Mappy, Ladybug Arcade, etc on the RGB output.  If it can not run those games, is that something that can be done in the future?

If those are the DPC+ games, then no, it will never run those. I don't have an ARM chip on the cart, so there's no way to get those running. Sorry!

 

Everything else 2600 wise is possible, though. The majority of commercial games are working fine. There's just a handful of mappers which I've yet to implement.

 

 

[+karri]

I am of course curious about the two 16k RAM blocks mapper and the 4k blocks that get mapped like in the SN cart. Do you plan to implement them also? (without the flip features)

 

[SainT]

26 minutes ago, karri said:

I am of course curious about the two 16k RAM blocks mapper and the 4k blocks that get mapped like in the SN cart. Do you plan to implement them also? (without the flip features)

 

I could add that, yes. I'm lacking on space in the FPGA for the SN audio, but the banking stuff I could add if people want it.

[+karri]

6 minutes ago, SainT said:

I could add that, yes. I'm lacking on space in the FPGA for the SN audio, but the banking stuff I could add if people want it.

I am not too familiar with the other existing banking schemes. Actually any nice scheme that allows me to load in blocks from ROM to RAM would be ok. As I am familiar with the SN by now I know that I could create demos and perhaps even complete levels on the 7800GD. It might also be a good tool for creating good quality videos using the RGB output. Currently I own only a RF output PAL 7800.

[Trebor]

*UPDATE*

The Dynamic Duo...

[SainT]

12 hours ago, karri said:

I am not too familiar with the other existing banking schemes. Actually any nice scheme that allows me to load in blocks from ROM to RAM would be ok. As I am familiar with the SN by now I know that I could create demos and perhaps even complete levels on the 7800GD. It might also be a good tool for creating good quality videos using the RGB output. Currently I own only a RF output PAL 7800.

Have a look at the existing mappers out there, I suspect there will be functionality which will already do what you want. There are lots of bank switching schemes with and without RAM. The mappers which allow a different memory space setup for Maria and CPU are good, such as BupChip and BankSet.

 

Any situation where you want a decent quality video out from the 7800, the GD works very well.

 

[+karri]

38 minutes ago, SainT said:

The mappers which allow a different memory space setup for Maria and CPU are good, such as BupChip and BankSet.

Actually I need different RAM memory space setups for Maria and CPU. In this way I can dump all my tiles to Maria RAM and all music plus sound effects to CPU RAM. I will toggle the RAM when the IRQ arrives. This leaves the ROM area free for moving sprites like hero, enemies and npc's. I also like the 4k blocks as it allows me to have a lot of variations in the animations. Plus I get rid of unused stuff when I have used them. So far the banksets I have seen use bigger blocks. Typically 16k. But perhaps there is a 4k block mapper out there.

 

I also prefer to think of the blocks as character animation space. Like:

 

$a000 hero
$c000 enemy

$e000 npc (or enemy in other orientation)

 

The other blocks like $8000, $9000, $b000, $d000, $f000 can be static. Is there such a mapper already?

[SainT]

No, there is nothing with less than 16K switching currently. Once the 7800GD is out there I'll have a look at other potential mappers.

[+sramirez2008]

14 hours ago, Trebor said:

*UPDATE*

The Dynamic Duo...

 

[Trebor]

*UPDATE*

[Eagle]

I'm doing recently some timing test with YM2151 on DragonFly and emulators.

@SainT I was wondering if you could test both files on GD7800 and let me know if you can hear any difference.

Thanks

 

RtypeTitleYMwait(PAL).a78 RtypeTitleYMnowait(PAL).a78

[Trebor]

*UPDATE*

Double your pleasure, double your fun...

[SainT]

25 minutes ago, Eagle said:

I'm doing recently some timing test with YM2151 on DragonFly and emulators.

@SainT I was wondering if you could test both files on GD7800 and let me know if you can hear any difference.

Thanks

 

No discernible difference to my ears, just fast as I was running on NTSC. 😆

 

If you need I can do an audio grab of both.

Edited April 27, 2023 by SainT

[Eagle]

OK. I trust your ears  

YM2151 manual saying that you need wait 68 internal clocks before writing next byte (about 35 Sally cycles)

But I couldn't find any more details, only I found about YM2612

Quote

I am quite confident from viewing the die shots, and it seems to be sufficiently confirmed from testing, that whenever you write a data value, BUSY gets set, and gets cleared exactly 32 cycles later. On the die shot it's just a 5-stage counter, not connected to anything else.
 

 

https://gendev.spritesmind.net/forum/viewtopic.php?t=386&start=825

 

For demos every cycle count  

 

[SainT]

6 minutes ago, Eagle said:

OK. I trust your ears  

YM2151 manual saying that you need wait 68 internal clocks before writing next byte (about 35 Sally cycles)

But I couldn't find any more details, only I found about YM2612

 

https://gendev.spritesmind.net/forum/viewtopic.php?t=386&start=825

 

For demos every cycle count  

 

Ah, interesting! You would be able to confirm that from the JT51 source code on GitHub as the GD uses JT's YM core. In fact I just had a quick look at it and it confirms "busy lasts for 32 synth clock cycles", so long as I'm looking at the right busy.

[Eagle]

@SainT Just one more to test if you don't mind.

Now is not about timing, it's just to compare how is play against original.

2 versions Pal and Ntsc (with sign )  just in case with console you are using

 

 

also link for JS7800 (if anyone want to listen)

Studiopolis YM2151 music

 

 

WAV generate from VGM for comparison

 

 

 

Thanks

 

StudiopolisYM(NTSC).a78 StudiopolisYM(PAL).a78

Edited April 27, 2023 by Eagle

[SainT]

Sounds very good! The (NTSC) 7800 is a little slower than the WAV -- I've been trying to listen to both at once, but it gets out of sync.  The 7800 plays well, though, no issues that I could hear.

[gambler172]

4 hours ago, SainT said:

 

No discernible difference to my ears, just fast as I was running on NTSC. 😆

 

If you need I can do an audio grab of both.

On Pal it is a little bit slower....but sounds good anyway