ATARI 7800 New Cartridge PCB with POKEY and YM2413 Support

[Eagle]

 @selgusThis should help a lot  

Cartridge_512kb_4kb_bankswitch.zip

[+selgus]

3 minutes ago, Eagle said:

 @selgusThis should help a lot  

Cartridge_512kb_4kb_bankswitch.zip 1.2 MB · 0 downloads

It does, indeed! Thanks!

 

I'll get to work looking at a YM2413 and SN76489 7800 cartridge.. guess I should start a new thread, since this was about the POKEY..

[Eagle]

I paid for SN around $1, for Pokey much more 

But now we have FPGA Trion T20 for SN² cart (7800GD uses T8)  

 

[+selgus]

26 minutes ago, Eagle said:

I paid for SN around $1, for Pokey much more 

But now we have FPGA Trion T20 for SN² cart (7800GD uses T8)  

 

Thanks! I was looking at your BOM and saw you source your SN chips from utsource.net. I was going to ask you before I found that reference, where you were getting your SN's from. I am skeptical about purchasing them from eBay, and getting counterfeit/fake chips.

 

I too, get many of my POKEY's from BallBlazer cartridges..

[Eagle]

Few VGM music YM2413/SN76489

 

 

YM_2413_SN.zip

[+selgus]

25 minutes ago, Eagle said:

Few VGM music YM2413/SN76489

 

 

YM_2413_SN.zip 79.16 kB · 0 downloads

Thanks, once I got the system running, I can use these as tests.

 

I needed to rework my gal inputs, as I don't have nearly the number of pins that you have on your cartridge.. to get the SN READY signal in there. Also, my address mapping is not as granular as you can do. I did do a version with the atf1500a cpld, but I'd like to stick with the gal22v10.

 

This might take me a little time..

[+karri]

10 hours ago, Eagle said:

FPGA Trion T20

Wow! That is really a cool chip. I loved the way bankswitching was designed on the SN cart. Flipping of directions was a great idea. My guess is that the fpga will also emulate the sound chips.

 

The only "bad" thing is that development of games is really locked to this cart. You cannot run the same games on flash carts and emulators.

 

But I really like the choice of sound chips YM2413/SN76489. This would provide high quality sounds.

[juansolo]

11 hours ago, selgus said:

I too, get many of my POKEY's from BallBlazer cartridges.

Likewise. I mainly use them for A8 stereo mods and repairs, a couple went into Dragonflys and another couple into stand alone cartridges. Sadly the times of being able to pick them up for less than £20 a pop are getting looking like they've past and I recently turned the last one in my stash into a Drelbs cart.

Edited February 13 by juansolo

[Eagle]

8 hours ago, karri said:

My guess is that the fpga will also emulate the sound chips.

Yes. Like I said before - 2xPokey, 2xSN, YM2151, YM2612, 4 channel Amiga style DMA covox and we will try Minnie.

YM2413 core is WIP, but it might work. We will have 24bit Pointers and Blitter, of course  

 

SN² cart it's compatible with SN cart and MariaECI. You can use in dev mode (transfer files by cable).

SD card I'm planning use for streaming video and/or music.

We have FPGA VGM player because almost every platform with Yamaha sound chips uses an additional Z80 processor just for playing music.

 

 

11 hours ago, karri said:

The only "bad" thing is that development of games is really locked to this cart. You cannot run the same games on flash carts and emulators.

This is flash cart (I don't want to make this cart another SD cart)

We have MiSTer FPGA core working for devs

 

I believe that is good start for possible future projects (e.g. new XM module and A7800 on FPGA)  

 

 

 

[+selgus]

9 minutes ago, Eagle said:

Yes. Like I said before - 2xPokey, 2xSN, YM2151, YM2612, 4 channel Amiga style DMA covox and we will try Minnie.

YM2413 core is WIP, but it might work. We will have 24bit Pointers and Blitter, of course  

Very impressive! Nice work!

 

What memory map locations are you using for the YM2413? I see 0x043f for the SN, 0x0460 for the YM2151.. I was planning on 0x046f for my YM2413 (yes, I needed to break down and move to the atf1500a epld, to generate all the signals needed for the sound chips and my rom/ram.. sigh).

[Eagle]

Quote

SN76489 	equ $43F
SN76489dual 	equ $43E

; FPGA VGM player for YM2151, YM2612, SN76489
VGMREG	equ $462; --  register number VGMPlayer
VGMDAT	equ $463; --  read/write register VGMPlayer

;VGMREG
;$00		- vgm_control - bit7 = on/off play, bit6 = on/off loop 
;$01 - $04 - 32bit vgm_play_address (to vgmdat)
;$05 - $08 - 32bit vgm_loop_address (to vgmdat)

YM2612BASE equ	$464		;($464-$467)

$468-$46F it's free

 

[+karri]

10 hours ago, Eagle said:

Yes. Like I said before - 2xPokey, 2xSN, YM2151, YM2612, 4 channel Amiga style DMA covox and we will try Minnie.

YM2413 core is WIP, but it might work. We will have 24bit Pointers and Blitter, of course  

 

SN² cart it's compatible with SN cart and MariaECI. You can use in dev mode (transfer files by cable).

SD card I'm planning use for streaming video and/or music.

We have FPGA VGM player because almost every platform with Yamaha sound chips uses an additional Z80 processor just for playing music.

 

 

This is flash cart (I don't want to make this cart another SD cart)

We have MiSTer FPGA core working for devs

 

I believe that is good start for possible future projects (e.g. new XM module and A7800 on FPGA)  

 

This is just too cool to be missed. The fpga player would free so much resources. It is really AMAZING what you are doing! And with this form factor it still looks like an ordinary cart!

 

I really LOVE the banks in the SN cart.  Will this cart also have banksets? Or perhaps the MariaECI makes banksets obsolete?

 

Time to invest in MiSTer.

[Zonie]

Nice work guys.