Open Hardware SNES Repro PCB with FeRAM support

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Oxinar
Posts: 2
Joined: Mon Mar 29, 2021 8:51 pm

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Oxinar »

RetroSwim wrote: Sun Mar 28, 2021 4:40 pm I've sent a DM to soniccd, but in a nutshell, it turns out my TL866 adaptor was to blame.

It allows you to program the 32Mbit EPROM in 4Mbit chunks. The A18-A20 selection logic was wired contrary to the silkscreening on my adaptor, so while each 4Mbit chunk was written correctly, they were written in the reverse order.

So with a combination of a byteswapped ROM, and operating my adaptor "correctly", I now got soniccd's board to work.

:)
Hi, I think I have this same problem, no matter what configuration I use, the game just doesn't work and I think the problem is with the adapter I use.
You couldn’t kindly post a picture of the adapter you use, maybe it’s the same one I use, and since you’ve managed to solve your problem, this may be the light at the end of the tunnel I need to make the blessed EPROM work.
RetroSwim
Posts: 11
Joined: Tue Mar 09, 2021 4:09 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by RetroSwim »

Oxinar wrote: Tue Mar 30, 2021 3:51 am
RetroSwim wrote: Sun Mar 28, 2021 4:40 pm I've sent a DM to soniccd, but in a nutshell, it turns out my TL866 adaptor was to blame.

It allows you to program the 32Mbit EPROM in 4Mbit chunks. The A18-A20 selection logic was wired contrary to the silkscreening on my adaptor, so while each 4Mbit chunk was written correctly, they were written in the reverse order.

So with a combination of a byteswapped ROM, and operating my adaptor "correctly", I now got soniccd's board to work.

:)
Hi, I think I have this same problem, no matter what configuration I use, the game just doesn't work and I think the problem is with the adapter I use.
You couldn’t kindly post a picture of the adapter you use, maybe it’s the same one I use, and since you’ve managed to solve your problem, this may be the light at the end of the tunnel I need to make the blessed EPROM work.
Image
Oxinar
Posts: 2
Joined: Mon Mar 29, 2021 8:51 pm

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Oxinar »

RetroSwim wrote: Tue Mar 30, 2021 6:45 pm
Oxinar wrote: Tue Mar 30, 2021 3:51 am
RetroSwim wrote: Sun Mar 28, 2021 4:40 pm I've sent a DM to soniccd, but in a nutshell, it turns out my TL866 adaptor was to blame.

It allows you to program the 32Mbit EPROM in 4Mbit chunks. The A18-A20 selection logic was wired contrary to the silkscreening on my adaptor, so while each 4Mbit chunk was written correctly, they were written in the reverse order.

So with a combination of a byteswapped ROM, and operating my adaptor "correctly", I now got soniccd's board to work.

:)
Image
:shock: That's the one I use, can you please give me the dip switch configuration you used?
RetroSwim
Posts: 11
Joined: Tue Mar 09, 2021 4:09 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by RetroSwim »

Literally just the opposite of what you expect.

DIP SW - 1-2-3 -- 1=ON
Bank 0 - 1-1-1
Bank 1 - 0-1-1
Bank 2 - 1-0-1
Bank 3 - 0-0-1
Bank 4 - 1-1-0
Bank 5 - 0-1-0
Bank 6 - 1-0-0
Bank 7 - 0-0-0
Kayumba
Posts: 246
Joined: Sun Mar 01, 2020 2:36 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Kayumba »

soniccd123,
On you PCB I see only one FRAM (FM18W08-SG) with 256Kbit of size.
How you do with all ROM's that checking SRAM size and block game if SRAM size is not the good one?
Do you patch headers to delate checksum ?
How you do make one chip FRAM to be compatible with all games ?
soniccd123
Posts: 46
Joined: Sat Jun 27, 2020 12:01 pm

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by soniccd123 »

Kayumba wrote: Mon Apr 26, 2021 6:23 pm soniccd123,
On you PCB I see only one FRAM (FM18W08-SG) with 256Kbit of size.
How you do with all ROM's that checking SRAM size and block game if SRAM size is not the good one?
Do you patch headers to delate checksum ?
How you do make one chip FRAM to be compatible with all games ?
Well, all the games that I tested that had somekind of copy protection by testing the SRAM size were successfully cracked using UCON64, Its very easy, even easier if the frontend is used.

FeRAMs are not as widely available in diferent sizes as SRAMs, even more so with the correct specifications and voltages for making repros, thats why I also did not include any other options, I think the FM1808 suits almost all the games concerning available space and at the same time is one of the most common 5V FeRAMs today. There are I think just 3 or 4 games that does not have any special chip and use more than 256Kbit of SRAM and all of them are quite obscure,
Kayumba
Posts: 246
Joined: Sun Mar 01, 2020 2:36 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Kayumba »

soniccd123 wrote: Tue Apr 27, 2021 12:57 am
Kayumba wrote: Mon Apr 26, 2021 6:23 pm soniccd123,
On you PCB I see only one FRAM (FM18W08-SG) with 256Kbit of size.
How you do with all ROM's that checking SRAM size and block game if SRAM size is not the good one?
Do you patch headers to delate checksum ?
How you do make one chip FRAM to be compatible with all games ?
Well, all the games that I tested that had somekind of copy protection by testing the SRAM size were successfully cracked using UCON64, Its very easy, even easier if the frontend is used.

FeRAMs are not as widely available in diferent sizes as SRAMs, even more so with the correct specifications and voltages for making repros, thats why I also did not include any other options, I think the FM1808 suits almost all the games concerning available space and at the same time is one of the most common 5V FeRAMs today. There are I think just 3 or 4 games that does not have any special chip and use more than 256Kbit of SRAM and all of them are quite obscure,
Thank you for answer.
- Do you know if there some option to reset or clear saved data?
- If i'am not wrong FM18W08-SG can also be used with 3.v ? (Power supply voltage : 2.7 V to 5.5 V)
- Is there some existing FRAM with bigger size ? (like 512Kbit or 1024Kbit)
soniccd123
Posts: 46
Joined: Sat Jun 27, 2020 12:01 pm

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by soniccd123 »

Kayumba wrote: Mon Apr 26, 2021 6:23 pm - Do you know if there some option to reset or clear saved data?
It really depends on the game, almost all games with save support have some way of clearing or creating new saves. Even so, in my tests, everytime I loaded a new game with a FeRAM chip containing saves from other games, it just saved over the old data.
Kayumba wrote: Mon Apr 26, 2021 6:23 pm - If i'am not wrong FM18W08-SG can also be used with 3.v ? (Power supply voltage : 2.7 V to 5.5 V)
Yes, the FM18W08-SG can handle 2.7V to 5.5V, the plain FM1808 is only 5V though (4.5V - 5.5V)
Kayumba wrote: Mon Apr 26, 2021 6:23 pm - Is there some existing FRAM with bigger size ? (like 512Kbit or 1024Kbit)
Probably yes, I don't really remember from the top of my head, but the FM FeRAM series have some diferent sizes (FM1206 for example is 4Kbit, it was officially used by SEGA in Sonic 3 carts), take a look at Ramtron modern and older catalogs, they're the manufacturer of the chip series. There must also be other manufacturers and FeRAM models, but I don't know them. Be advised however that FeRAM is quite expensive and it scales with storage size.
Kayumba
Posts: 246
Joined: Sun Mar 01, 2020 2:36 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Kayumba »

Thank you for information :beer:

« the plain FM1808 is only 5V though (4.5V - 5.5V) »

That’s mean I cannot use it for 3v flash Eprom ?
I can not find this line in datasheet, what's line name it can be?
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by lidnariq »

No, that means it's not usable in a 3V system (like the N64 or GBA).

If a part can be used at 5V, and you're using it in a 5V system, you should place it on the "5V native" side. If you're also using 3V parts with translation for those 3V parts, only the parts that need translation should be behind the extra ICs.
Kayumba
Posts: 246
Joined: Sun Mar 01, 2020 2:36 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Kayumba »

lidnariq wrote: Wed Apr 28, 2021 11:05 am No, that means it's not usable in a 3V system (like the N64 or GBA).

If a part can be used at 5V, and you're using it in a 5V system, you should place it on the "5V native" side. If you're also using 3V parts with translation for those 3V parts, only the parts that need translation should be behind the extra ICs.
What’s it mean « "5V native" side » ?
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by lidnariq »

The side that doesn't need translation because everything already is communicating with 5V for logic 1 and 0V for logic 0.
Kayumba
Posts: 246
Joined: Sun Mar 01, 2020 2:36 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Kayumba »

lidnariq wrote: Wed Apr 28, 2021 4:32 pm The side that doesn't need translation because everything already is communicating with 5V for logic 1 and 0V for logic 0.
:D :beer: :beer: :lol:
Kayumba
Posts: 246
Joined: Sun Mar 01, 2020 2:36 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by Kayumba »

Hi soniccd123,

I would like to use 1024 Kbit FRAM like FM28V100 or CY62128EV30LL vs 256Kbit.
FM18W08 : pin 1 (A14) and pin 26 (A13) have different connections for LoROM and HiROM.
pin 1 :
LoROM cart 39 = A14
HiROM cart 42 = A17

pin 26 :
LoRom cart 38 = A13
HiROM cart 41 = A16

Should I do the same with 1024 Kbit FRAM for A13 and A14 address pins ?
Thank you
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Open Hardware SNES Repro PCB with FeRAM support

Post by lidnariq »

Note that memories with "V" in the part number are 3.3V devices: they will be damaged by being operated at 5V, and will damage 5V parts if they are operated at 3.3V without voltage translation.
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