Still use SRAM or move to eeprom ?

For anything related to cart (SRAM, SF2 mapper, audio, CD mode 1, ...)

Moderator: BigEvilCorporation

Post Reply
User avatar
KanedaFr
Administrateur
Posts: 1114
Joined: Tue Aug 29, 2006 10:56 am
Contact:

Still use SRAM or move to eeprom ?

Post by KanedaFr » Sun Mar 27, 2016 10:12 am

Hi
for new game, does it still make sense to use SRAM ?
I mean, why not use (now) low cost eeprom and not sram + battery holder + battery ?

The only thing I saw is emu support, since eeprom support is per game.
because cost is no longer a problem, no ?

User avatar
Sik
Very interested
Posts: 623
Joined: Thu Apr 10, 2008 3:03 pm
Contact:

Re: Still use SRAM or move to eeprom ?

Post by Sik » Sun Mar 27, 2016 10:50 am

Fusion seems to look at the header to determine if the EEPROM is used since it's the only emulator that doesn't barf on Game Toshokan if you don't null out the EEPROM functions (it's probably looking at the fact that external memory starts and ends in the same address). Flashcart support is a much bigger issue since they usually only emulate SRAM instead.

Also the fact that EEPROM is harder to program so that probably discourages people from using it in favor of SRAM which is trivial to use (and you can even use its data directly from there).
Sik is pronounced as "seek", not as "sick".

Mask of Destiny
Very interested
Posts: 559
Joined: Thu Nov 30, 2006 6:30 am

Re: Still use SRAM or move to eeprom ?

Post by Mask of Destiny » Mon Mar 28, 2016 10:21 pm

As far as emulator support is concerned, it's easy to detect whether a game uses EEPROM (generally indicated in the header in the manner Sik mentions), but there's no reliable way to determine how it should be actually wired up and what capacity of EEPROM it has short of having a list of EEPROM games containing the relevant metadata. It would be nice if we had a ROM format that allowed for extra metadata describing things like EEPROM hardware and weird mappers so that new homebrew using that hardware would just work, but I have my doubts such a format could gain traction at this point.

If you're planning on doing a hardware release though, going with EEPROM seems like a slam dunk. Lowers your part count and there are far fewer traces to route for your save hardware (assuming a serial EEPROM anyway). It is indeed harder to program, but the additional programming burden is not extreme and it seems to me the unit cost advantages are worth it.

User avatar
KanedaFr
Administrateur
Posts: 1114
Joined: Tue Aug 29, 2006 10:56 am
Contact:

Re: Still use SRAM or move to eeprom ?

Post by KanedaFr » Tue Mar 29, 2016 12:45 am

Yes, I'm talking about new release, hardware side.

The blank PCB we can buy are w/ or w/o SRAM
nothing about (serial) eeprom
I do understand these PCB are mainly used for repro but, on our side, what would be the best bet ?
from capabilities and price side...

Need to compare SRAM / EEPROM (/ NVSRAM / FeRAM)
save capacity vs IC(s) price vs board price vs life time...

User avatar
Sik
Very interested
Posts: 623
Joined: Thu Apr 10, 2008 3:03 pm
Contact:

Re: Still use SRAM or move to eeprom ?

Post by Sik » Tue Mar 29, 2016 12:59 am

Mask of Destiny wrote:It would be nice if we had a ROM format that allowed for extra metadata describing things like EEPROM hardware and weird mappers so that new homebrew using that hardware would just work
Don't even dare >=|

Mind you though, there's still some space left in the ROM header that obviously Sega won't populate anymore =P May as well use that for extensions.
Sik is pronounced as "seek", not as "sick".

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest