What model is the backup battery?

bitrate · Post by **bitrate** » Sat Jan 17, 2009 10:18 pm

3DO Experience wrote:grrrr but what is it's function on the 3DO?

bitrate wrote:The CMOS SRAM handles game saves/high scores/etc.

Post by **3DO Experience** » Sun Jan 18, 2009 4:20 am

OK I understand that it was made for that but the 3DO saves these in the NVRAM. So therefor I asked what is it's function on the 3DO?

MrAshDarksideTM · Post by **MrAshDarksideTM** » Sun Jan 18, 2009 4:26 am

That is precisely it's function in the 3DO.

bitrate · Post by **bitrate** » Sun Jan 18, 2009 4:36 am

3DO Experience wrote:OK I understand that it was made for that but the 3DO saves these in the NVRAM. So therefor I asked what is it's function on the 3DO?

The NVRAM on the 3DO is composed of SRAM and the Lithium battery.
So the function of the SRAM/Lithium battery combination is to provide NVRAM for game saves/high scores/etc.

Post by **3DO Experience** » Sun Jan 18, 2009 8:53 pm

oooooooh I thought they were saying it had both NVRAM and SRAM...

bitrate · Post by **bitrate** » Mon Jan 19, 2009 1:47 am

3DO Experience wrote:oooooooh I thought they were saying it had both NVRAM and SRAM...

It does have both NVRAM and SRAM. The NVRAM IS the SRAM.

WindowsKiller wrote:
3DOKid wrote:Alright this is interesting - what does the battery backup controller actually do?
Monitoring whether the system is mains-powered or not. The battery is not constantly used to power the SRAM, only when the unit is turned off.

To elaborate, since there seems to be some interest in this topic:

Monitoring whether the system is mains-powered or battery-powered, and switching between the two, is one important function of the battery back-up controller.

An equally important function of the battery back-up controller is to place the SRAM IC into operational mode (under mains power) or standby mode (under battery power).
When the battery back-up controller pulls the SRAM's chip enable (CE) pin high, all read/write privileges are revoked and the SRAM enters standby mode where current draw is drastically reduced.

Post by **3DO Experience** » Mon Jan 19, 2009 6:43 pm

bitrate wrote:It does have both NVRAM and SRAM. The NVRAM IS the SRAM.

Yes I understand that now, what I should have said was I thought that you were saying it had SRAM and physical NVRAM. It didn't make sense to me to have two separate sets.

Sounds like it might be wise to swap the battery for a removable one... when it dies that is.

MrAshDarksideTM · Post by **MrAshDarksideTM** » Mon Jan 19, 2009 6:58 pm

3DO Experience wrote:
bitrate wrote:It does have both NVRAM and SRAM. The NVRAM IS the SRAM.
Yes I understand that now, what I should have said was I thought that you were saying it had SRAM and physical NVRAM. It didn't make sense to me to have two separate sets.

Sounds like it might be wise to swap the battery for a removable one... when it dies that is.

Thats what I'm going to do when the time comes, people do it with SNES games.

Post by **3DO Experience** » Tue Jan 20, 2009 2:32 am

I did it to an old Zelda cart, the original Zelda mind you. I used the Game Action Replay to capture the point and then did the mod. Only prob was it didn't fit in the cart right do to being thicker and eventually the cart stopped working altogether.

bitrate · Post by **bitrate** » Tue Jan 20, 2009 6:16 am

Mobius wrote:Now I wonder what kind of memory is in the memory expansion.

Wonder no longer

Mobius · Post by **Mobius** » Tue Jan 20, 2009 7:46 am

bitrate wrote:
Mobius wrote:Now I wonder what kind of memory is in the memory expansion.

Wonder no longer

Damn, is there no permanent 3DO storage solution? Are our saved games destined to be lost forever???

bitrate · Post by **bitrate** » Tue Jan 20, 2009 8:13 am

Mobius wrote: Damn, is there no permanent 3DO storage solution? Are our saved games destined to be lost forever???

You can always wire a replacement cell (or other 3 volt source) in parallel with the old cell while removing the old cell in order to retain your saves.