JOTEGO
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Support for Pac-Mania. JTCOMMND for Pocket
🕑 Added 2024-04-05 18:13:45 +0000 UTCEspañol abajo
Work continues toward closing the JTSHOUSE and JTTMNT betas. More GFX features have been implemented for JTSHOUSE, fixing problems in Splatter House and Galaga '88. We also bring support for Pac-Mania in this week's update.
Reports about music instruments going crazy in Splatter House led to detailed research. It turns out that Namco's sound driver in this system does not comply with Yamaha's specifications. After checking with two other researchers, we all agree that the Yamaha chip cannot be programmed correctly the way Namco was doing it.
The problem is that the Yamaha sound chip requires about 18 microseconds between each data write, but Namco's software is executing writes at a 7-microsecond rate. This time interval is not emulated in MAME, so all writes in emulation execute correctly. However, in real hardware, many writes fail to take effect, and the sound instruments are not configured correctly.
It is hard to imagine how this was missed when developing the games. They must have used a different setup for music composition. Did the composer never listen to the music on the final system? Anyway, the core by default uses a hardware connection to halt the CPU until a write takes effect. This is a connection that does not exist on the original PCB. The original PCB would require a software patch to prevent this problem. You can disable this fix in the DIP switches.
We did more research on the YM2203 chip. This chip, used in Bubble Bobble, The New Zealand Story, and many others, has an AY-3-8910 compatible module inside. Hence it produces two types of sound: Yamaha's FM sound and square wave sounds. We discovered that a typical connection for the analog output done to AY-3-8910 would not work correctly in YM2203 and understood the underlying mechanism. We have only seen this incorrect connection on the two systems mentioned above. The cores have been modified to model this behavior. This is mostly noticeable in sound effects. This is not as bad as the problem in Namco System 1, so I have not added an option to disable the distortion.
We found what caused the volume drop in JTCPS15/JTCPS2. The volume has been restored in today's update. JTSF, the core compatible with Capcom's Street Fighter 1, is still affected, although no one had noticed it. We'll get that one in the next update.
As we measured YM2203's PSG features and YM3014's output impedance, the sound of some cores will be a bit different after this update. We still have a few more chips to measure before closing this chapter.
I am holding a presentation of the JTCORES repository and JTFRAME framework to other FPGA developers tomorrow. My hope is to get more developers working within the JTCORES repository. I hope I can show the benefits of this project to the community.
The JT1943 beta period for the Analogue Pocket is over and the core is now public. We receive a new Pocket beta: JTCMMND, compatible with Capcom's Commando hardware.
That's all for this week!
Español
El trabajo continúa enfocado a concluir las betas de JTSHOUSE y JTTMNT. Se han implementado más funciones gráficas para JTSHOUSE, solucionando problemas en Splatter House y Galaga '88. También traemos soporte para Pac-Mania en la actualización de esta semana.
Informes sobre instrumentos musicales que desvarian en Splatter House motivaron una investigación detallada. Resulta que el controlador de sonido de Namco en este sistema no cumple con las especificaciones de Yamaha. Después de verificarlo con otros dos investigadores, todos coincidimos en que el chip de Yamaha no puede ser programado correctamente de la manera en que lo hacía Namco.
El problema es que el chip de sonido de Yamaha requiere unos 18 microsegundos entre cada escritura de datos, pero el software de Namco ejecuta las escrituras a una tasa de 7 microsegundos. Este intervalo de tiempo no está emulado en MAME, por lo que todas las escrituras en la emulación se ejecutan correctamente. Sin embargo, en el hardware real, muchas escrituras no surten efecto y los instrumentos de sonido no se configuran correctamente.
Es difícil imaginar cómo se pasó por alto esto al desarrollar los juegos. Deben haber utilizado equipos distintos para la composición musical. ¿El compositor nunca escuchó la música en el sistema final? De todos modos, he preparado el núcleo para que use una conexión de hardware especial. Esta detiene la CPU hasta que la escritura en el chip de sonido surta efecto. Esta es una conexión que no existe en el PCB original. El PCB original requeriría un parche de software para prevenir este problema. Puedes desactivar esta corrección en los interruptores DIP.
Hicimos más investigaciones sobre el chip YM2203. Este chip, utilizado en Bubble Bobble, The New Zealand Story y muchos otros, tiene un módulo compatible con AY-3-8910 en su interior. Por lo tanto, produce dos tipos de sonido: el sonido FM de Yamaha y sonidos de onda cuadrada. Descubrimos que una conexión típica para la salida analógica del AY-3-8910 no funcionaría correctamente en YM2203 y entendimos el mecanismo subyacente. Solo hemos visto esta conexión incorrecta en los dos sistemas mencionados anteriormente. Los núcleos han sido modificados para modelar este comportamiento. Esto es más notable en los efectos de sonido. La distorsión no es tan grave como el problema en Namco System 1, por lo que no he añadido una opción para anular este efecto.
Encontramos lo que causó la caída de volumen en JTCPS15/JTCPS2. El volumen ha sido restaurado en la actualización de hoy. JTSF, el núcleo compatible con Street Fighter 1 de Capcom, todavía está afectado, aunque nadie lo había notado. Lo arreglaremos en la próxima actualización.
Como completamos las medidas de las características PSG del YM2203 y la impedancia de salida del YM3014, el sonido de algunos núcleos se notará un poco diferente en esta actualización. Todavía tenemos algunos chips más que medir antes de cerrar este capítulo de sonido.
Mañana estoy organizando una presentación del repositorio JTCORES y el entorno JTFRAME para otros desarrolladores de FPGA. Mi esperanza es conseguir más desarrolladores trabajando dentro del repositorio JTCORES. Espero poder mostrar los beneficios de este proyecto a la comunidad.
El período de beta de JT1943 para la Analogue Pocket terminó y ahora el core es público. Recibimos una nueva beta para Pocket: JTCMMND, compatible con el hardware de Commando de Capcom.
¡Eso es todo por esta semana!
Comments
James Dexter
The Pacmania core on the pocket is great but is it possible to save the setting changes in the service menu? I can make the changes but they are not saved so make no difference on the game. Any ideas please?
Dels
Any plans to do "Namco Classic Collection Vol. 1 or Vol. 2"? Vol. 1 has "Galaga Arrangement". A gem of a game not found anywhere.
Kent Pendragon
Really looking forward to your Patreon-only cores becoming public. I am a JT Patreon but personally, I am not interested in beta releases at all (never installed the jtbeta.zip) — so I patiently wait for your work to become public.
Gavin Turman
Hi Jotego. Thanks for all the awesome work. I’m setting up a new sd card and am having issues getting the roms to download after running update all. I’ve checked to make sure that Jotego premium is enabled as well as to receive roms but it’s only downloading some of the roms. I’ve also put the jtbeta.zip file in games/mame folder but still no luck. Any ideas?
INAKI ECHEVARRIA LARRINAGA
Hi Jose, this may be early but have you considered giving support to RndMnkIII's Analogizer ( special GBA cartridge for enabling the output of an RGB signal with the native video directly from each supporting openFPGA core which also enables direct input via the use of original console controllers via SNAC adapters ) for the Analogue Pocket to your jtframe ? This seems to be getting attention and openFPGA cores like NeoGeo, NES, SNES have already been added this support and others are on its way to support it. I know your work schedule is supper packed and man, we are so lucky to have such a talented work force from you... so this is just curiosity and/or a suggestion :)
Owlnonymous
The games work great! Splatterhouse sounds and plays great. I adore Galaga ‘88 now.
Jakob Schmid
I'm fascinated with the Splatterhouse sound issue - do I understand it correctly, that the hardware arcade version will not receive all instrument setup data and the instruments patches will sound wrong? And does that mean that the MAME version might sound like the composer intended, and the real hardware and now also the MiSTer version will sound 'incorrect' from the point of view of the composer (but obviously correct in terms of emulating the real hardware)? If that is the case, that is a very neat discovery!
Brian Birkinbine
Will the presentation be available to the general public? regarding "I am holding a presentation of the JTCORES repository and JTFRAME framework to other FPGA developers tomorrow. My hope is to get more developers working within the JTCORES repository. I hope I can show the benefits of this project to the community."
Salvador Perugorria Lorente
JTTMNT y JTSIMSON, ¿ya no funcionan en MiST? Saludos :-)
VINSTER
Thanks for your work Jotego! For Analogue Pocket I'm noticing every time I try to update, or replace older cores, certain settings in games are either flipped (bad dudes,cps1,aliens), in test mode (ghouls n ghosts), or coinage is requiring 4/1 credit, or free play is on, & bubble bobble needs rom switched in settings.
Faye Salwin
or right click and choose save - it is opening by default
Holger Lagerfeldt
macOS/Safari browser. Switch to Google Chrome and it downloads as "jtbeta.zip".
Holger Lagerfeldt
Same here: not easy to locate (although it seems to be a Patroen layout issue - it won't show up in the overview, directly) and it downloads as "beta.bin" although the link says "jtbeta.zip".
Adrien Duchemole
Thanks a lot for this update I can't wait to see more of these namco system 1 games (marchen maze, yôkai dôchûki, and others, they're really great games !!) I may have a question about karate champ on pocket I can't manage to build bootable roms of the VS game I just can play the original game (same problem with the roms i got from update all) there is also something strange about that game, but on mister fpga, music is still played during the fights I've never seen any arcade version with that feature thanks, and good luck !!
JOTEGO
The beta file has not changed since January. I only post it for new users. When old patrons need to update the beta file, I write it in big bold letters in the post. I try to change it very few times a year. I do not know why it gets unzipped for you. Could it be your web browser settings?
Pat Jones
I don't understand why the jtbeta.zip downloads as beta.bin., it does not work when placing it the games/mame folder. Last jtbeta update I had to find find the proper jtbeta zip file from the JT Discord, the only way I found out how to do that was from reading the comments. I'm sure I'm missing something but I feel like updating the beta.zip should be easier to figure out, I used to be able to download the correct zip file directly from this page.
Alan Roth
Thank you!!
Mat Azel
this is super interesting and will keep my eyes peeled for this :D thanks a million for finding this guys !!
JOTEGO
Yes, it means exactly that. I am not sure how many games are affected, but Splatter House and Pac-Mania would need a ROM patch in the original hardware.
ronalvel .
Gracias por seguir perfeccionando los nucleos !!!
Mat Azel
"The original PCB would require a software patch to prevent this problem. You can disable this fix in the DIP switches." wait, what does that mean for the pcb? a patch for the prg eprom? just got a tank force pcb this week, so I'm super curious of the difference in sound (I'm also planning on getting the darksoft multi for it)
Fabricio
Thank you!😊
JOTEGO
I think it is correct now but I’ll check it again.
Rautz
Happy #JTFriday everyone. Thanks to Jose and the team and anyone else helping behind the scenes. Good luck with the presentation tomorrow, I too hope more devs see the benefit and develop within jtcore' repository. Churry
Televicious Goober
Pac-mania! 😍
Fabricio
Thank you for the update! The music for Double Dragon 1 still is a little low. Don’t know if it’s only at my side or if this is an issue. Ps: sorry about my English
ER
It’s great to hear about the sound fixes even if I don’t understand everything :), other than the original developers did some weird stuff that happened to work on the original hardware which may have responded in some weird undocumented way, which emulator/core developers have to discover and then work around. Thanks!
Timothy Watson
Looking forward to downloading. Thank you!
Retroplayer
Awesome work! Great to see Commando for the pocket. Thank you.
Denny Letourneau
Splatterhouse music seems to be correct with the fix on (i think)! Thank you so much.
Philippe Losier
Great job !!! I love you work
Shannon Thomasson
Woot! Downloading tonight!
Big Al.
As Usual Thank you and the team for the work done..👍
Mark Saunders
Fantastic work you guys are doing loving the audio quality control you’re looking into . Pacmania to be superb to be played on a cabinet ! Yay
pie19988
In the wise words of moist critical..."yeah baby that's what I've been waiting for" Super hyped for this!
Pixel Cherry Ninja
Thanks JT and team, have a good weekend
Dwight Davis
Let's goo
