The present systems include a memory module containing a plurality of RAM chips, typically DRAM, and a memory buffer arranged to buffer data between the DRAM and a host controller. The memory buffer includes an error detection and correction circuit arranged to ensure the integrity of the stored data words. One way in which this may be accomplished is by computing parity bits for each data word and storing them in parallel with each data word. The error detection and correction circuit can be arranged to detect and correct single errors, or multi-errors if the host controller includes its own error detection and correction circuit. Alternatively, the locations of faulty storage cells can be determined and stored in an address match table, which is then used to control multiplexers that direct data around the faulty cells, to redundant DRAM chips in one embodiment or to embedded SRAM in another.