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battery eliminator

Replace the original 5101 NVRAM chip.

No batttery needed anymore, the used F-RAM chip stores NVRAM data without a battery backup.

I have created two versions.

Version1 supports pinball MPUs which need dual CE ( like Gottlieb system80 or Williams SYS3 & SYS4 )

Version2 supports pinball MPUs which need dual CE and use seperate pins for input/output ( like Gottlieb system1 or Atari). Version2 works also in systems where version1 works.

Note: both versions will work also on pinball MPUs with 5101 NVRAM which do not have special requirements for 'dual CE' or seperate in/out. ( e.g. Bally MPU )

Can be used with F-RAM memory FM16W08 or FM18W08. Either use JLCPCB assembling service (BOM contains FM18W08 which must be preordered) or solder yourself, digikey links below.

FM16W08 or FM18W08


SN74LS244DBR ( Version2 only )

Version 1 on Gottlieb System80 MPU
Version2 on Atari Gen2 MPU