FPGAgen with HiFi PCM (MiST)
I have compiled a version of the Megadrive core for MiST with HiFi PCM interpolation of samples. You have to enable it on the OSD menu (F12). Have fun!
(file attached)
2019-04-11 19:01:54 +0000 UTC View Post
JOTEGO posts
Audio Comparison PCM with Linear Interpolation
Following on the previous topic about linear interpolation. I have improved it on the Megadrive sound chip core JT12. This core already made a x2 interpolation by default. Now I have extended it to arbitrary numbers.
This increases the sound quality of the Megadrive but for games with very poor samples the difference in sound is very large so I guess that somepeople may prefer the aliasing sound just because ...
2019-04-11 11:08:25 +0000 UTC View PostNeoGeo Sound: Linear Interpolation
One thing present in the real YM2610 and missing in emulators (as far as I know) is linear interpolation of samples. This is important because YM2610 had a variable sample rate channel which was used sometimes to play different notes using a single sample. Missing interpolation creates high frequency noise and aliasing. Are you going to notice it? The better your speaker system (and your musical ears) the most you will notice the difference.
The image h...
2019-04-08 08:01:01 +0000 UTC View Post
Development Update
(español abajo, 日本語は下記)
I have spent the last 10 days or so with NeoGeo sound: YM2610. Progress is good with the following features already present: FM sound, PSG sound, ADPCM-B sound. Missing things: ADPCM-A channels (sound broken now) plus an ADPCM filter. The code is in the usual repo and I am keeping Furrtek posted about it.
Payments for last c...
2019-04-01 21:03:06 +0000 UTC View PostSurprise, surprise!
(español abajo)
I needed a break from full system cores. So I finally started adding YM2610 (NeoGeo) capabilities to my OPN FM core JT12 (used in the Megadrive and CAPCOM arcade cores). I wrote the RTL code for the first 6 ADPCM channels yesterday. But before hooking those up, I had to test the FM output pitch. Surprisingly, default JT12 settings for...
2019-03-23 11:00:02 +0000 UTC View PostPopeye: Early High Res Games
Scralings, one of the director patrons, asked me to look at 1982 Nintendo's Popeye arcade. It looked like an easy game to port. So I accepted... only to find out that this game has the oddest graphics system.
The character layer is pretty much standard, but the background is drawn by the CPU on a RAM chip, pretty much like any 8-bit computer would do. But then, sprites are the most obscure thing I have seen. They use a special clock, at twice the rate of the character layer and the outp...
2019-03-21 11:06:54 +0000 UTC View Post1943 Sprite Flipping
When you have to store the image for a sprite, you usually want to save memory space. If possible too, you want to make your sprite driver software simple too. Arcades like Ghosts'n Goblins or Contra (Gryzor) achieves this by having two bits associated with each sprite on the screen: one for horizontal flip and the other for vertical.
When these bits are set, the sprite coordinates are reversed. The sprite pixels are not scanned from 0 to 15 but from 15 to 0. In the hardware desig...
2019-03-19 10:00:01 +0000 UTC View Post1943 for MiSTer
(español abajo)
When I went shopping for boards last Saturday, the seller had my children play a pandora box. My eldest kid found 1943 and played it. He has been playing a lot to the MiST version during the core development. On the way back home he told me: Dad, I like more your 1943 game. When I asked why, he said that man's 1943 felt like sloppy. Controls didn't respond as good 2019-03-12 10:01:00 +0000 UTC View Post
Ghosts'n Goblins Credits Added
I have updated the MiSTer repository with the new optiosn for Ghosts'n Goblins:
-Pause screen with patron credits (P key in MiST, F4 in MiSTer)
-Fixed top two lines of the screen (sprites were missing in those lines)
-Added ROM load option
-New ROM generation file easier to use in MiST (a .bat file)
Please find attached both MiST and MiSTer files. Eventually the MiSTer file will get available through the integrated update system too.
Bruno Silva helped ...
2019-03-10 22:06:20 +0000 UTC View PostWent shopping!
(español abajo)
Thanks to your support I visited a sellert today and bought new games to translate to FPGA. I am really excited about these titles. All the PCB's worked but Rastan Saga had no sprites on screen and Nemesis (Gradius) seems to be completely broken. I may repair them as part of the conversion process.
I do have a backlog of tasks but I didn't want to let pass the opportunity of visiting this seller and I think it was worth it. Please let me know what is yo...
1943 MiST File
Please find attached the MiST core for 1943 (beta)
2019-03-05 21:55:42 +0000 UTC View Post1943 Beta Release
Here it is, resurrected from the PCB era, the 1943 arcade from CAPCOM. This is an awesome game with a lot of technical improvements over the prequel 1942. This has been a bit easier to do than the previous two games as I am getting more used to CAPCOM technology of the time. This beta version has two known problems: 2019-03-05 21:53:54 +0000 UTC View Post
Ghosts'n Goblins Pause Credits
As I am brushing up 1943 for release, and as 1943 and Ghosts'n Goblins share pretty much the same sprite engine, I found an old bug. In the current core of GnG sprites are not drawn for the first two lines of the screen. This was happening in 1943 too but it was more obvious as many planes fly off the edges of the screen. So I have fixed it in both cores now and I have to make a new GnG release.
I am going to add a pause feature to this new release and ...
2019-03-02 19:39:48 +0000 UTC View PostMultirom support
1943 core will feature rom load directly from the OSD menu. There are several versions of the game and it was worth doing it.
Bruno Silva prepared the ROM files for all different sets and saved me a ton of time. Thanks a lot!
On the sad news side, there won’t be a core release for February. This core needs more memory bandwidth than the other ones and I need to write a new ROM driver to deal with it. At least one more week of work.
2019-02-28 07:05:10 +0000 UTC View PostYM2610 and collaboration with Furrtek
Furrtek's amazing job on the NeoGeo is quickly getting to the point where we need sound on it. One of my Yamaha cores, the JT12, supports YM2203, which is the chip part of Ghosts'n Goblins. It is also the FM core of YM2610 -the NeoGeo sound chip. So Furrtek actually shared some of his Patreon's earnings as a token of appreciation for the JT12 work I had don...
2019-02-25 15:24:57 +0000 UTC View Post1943 Tricks for better CPU performance
(español abajo)
I have finished analyzing 1943 schematics and I have started writting the new core. This game looks much more advanced than 1942 but if you were to check only the CPUs it is the same: two Z80 CPUs. However, there are things they have done to the GPU (which is made of discrete parts, rather than a large chip) to free up the CPU even more.
First, they seem to reuse the DMA scheme for sprites that Ghosts'n Goblins had. I cannot guarantee it is 100% identical because ...
2019-02-21 12:00:14 +0000 UTC View Post1942 Public Release
After a horrible week trying to fix one bug, I finally make the 1942 core public. The MiST binaries are attached to this post. MiSTer binaries are in Sorleig's repository and you should be able to get updates following the standard MiSTer procedures.
The public version shares the same romset as MiSTer. Note that the previously available beta for $3+ patrons used a different romset. The script to generate the romset is inside the zip file. Remember to rename the file a.1942.rom 2019-02-19 17:55:59 +0000 UTC View Post
Next game!
This is being a slow week. I have been working to prepare the public release of 1942 and Ghosts'n Goblins cores. Most of this work is towards increasing reliability, and uniformity between the two cores and between the MiST, MiSTer and ZX-UNO versions. Very gray work but I hope it will pay back when I move onto the next game as the framework will be more stable then.
And speaking of the next game... which one of these would you like to see done next?&nb...
2019-02-14 12:30:58 +0000 UTC View PostGhosts'n Goblins Update
(español abajo)
I am re-factoring the GnG & 1942 cores to share as much code as possible. This helps add new features to all cores easily. As part of this effort, the Ghosts'n Goblins core now supports keyboard on MiST. The imaginary staircase bug is fixed too. The attached file is for MiST.
I have asked Sorgelig to update the MiSTer core too (download from 2019-02-09 20:11:19 +0000 UTC View Post
Especial 1942 y MiSTer en AmigaWave (español)
Los compañeros de AmigaWave, y en especial Carlos, le han dedicado una buena parte de su último programa a MiSTer y al core de 1942 para MiST. Es un repaso muy interesante para todos los nuevos a MiSTer. Os dejo el enlace al vídeo justo donde empieza esta sección.
2019-02-07 10:47:18 +0000 UTC View Post1942 MiSTer Review on Youtube (English)
SmokeMonster made a special for the beta release yesterday. Very interesting show going through computer ports of the arcade too. I love the way SmokeMonster captures the beauty of these systems.
2019-02-07 10:31:16 +0000 UTC View Post1942 MiSTer Beta
It is finally here! Find the 1942 core attached to this post. Right now, as this post comes up Smoke Monster is showing this core on his YouTube channel. Join him in this virtual unboxing!
I expect to make the public release this weekend for MiST and MiSTer. Sorgelig will handle the MiSTer version directly.
2019-02-07 02:01:01 +0000 UTC View Post1942 MiSTer Update
It is finally running in MiSTer. I got some help from Sorgelig to get it working while I was waiting for the cable I needed. I will release the beta tomorrow for $3+ Patrons. There are a couple of things I need to fix before the public release. Basically the CAPCOM logo does not show up correctly on the title screen. Otherwise the game seems perfect.
I would like to make the public release this weekend and move on to the next game/board.
2019-02-05 16:34:52 +0000 UTC View Post1942 for MiST Beta Release
Find attached to this post the MiST core and the needed ROM.
I wanted to do a combined release with the MiSTer version yesterday but it has proven impossible for a large number of technical reasons. So please give me a couple of days to wrap it up.
This core features the pause screen with patron names. Just enter the OSD menu to set the pause.
There is a glitch with some sprites. It will be fixed in the final release. I also plan to add keyboard support so ...
2019-02-03 10:04:11 +0000 UTC View PostWhich platform do you use?
It will help me to know which platforms are popular.
2019-02-02 11:00:04 +0000 UTC View Post1942 Port Completed
I finished all the pieces and now the game works in MiST. Jeez, it's so much to play. It feels easier than in the emulator and more engaging. I will work in the MiSTer/ZX-UNO conversions now.
The audio of this post has been captured directly from MiST.
Stay tune because I will release it for Patreons very soon.
2019-01-31 23:13:05 +0000 UTC View Post1942 Almost Ready
(español abajo)
It's almost there! After struggling with a sprites issue I concluded that the schematics available for 1942 must belong to a different CAPCOM game. Most of it seems to match but sprite addressing is different. The schematics assume that only 8kB x 4 of sprite ROMs are available but there are indeed twice that. I still have to finish up the sprite generator and wrap up a few items -like the suggested keyboard support. But I will release MiST and MiSTer cores for $3+ ...
Announcements
(español abajo)
Thank you all for showing so much interest during this first week. It has motivated me a lot. Maybe too much!
We are starting to be a community where we can push to get more of these games faithfully convert to modern hardware so they won't die out. I have received a lot of support this week and although I understand that people do it because they love these games and technology, I was thinking how to give back more. Starting from the 1942 core I ...
2019-01-28 11:48:24 +0000 UTC View PostGot MiSTer with goodies
I bought a mister last weekend. I only had a MiST and a ZX-UNO before. But as many people use this platform too and it has many great quality cores I decided to join in.
And well, Antonio Villena kindly sent me the add-ons for mister so I am all set. I hope to deliver some cores directly for MiSTer in the future too.
2019-01-25 13:28:30 +0000 UTC View Post