FBE Research ZMF100a – h/z-100 memory upgrade conversion kit. This a ZMF100a by FBE. This is a modification “kit” for the Zenith/Heath Z-100 computers using the old motherboard. With this modification, you can can use industry standard 256K DRAMs instead of the 64K DRAMs. This allows up to 768K of memory to be added without wasting a S-100 slot! Includes original installation manual. Reach out if you have any questions – we’re happy to help.