Refurbished IBM 6400-i20 Line Matrix Printer, 2000 LPM, Ethernet IPDS, Quiet Cabinet. IBM 6400-i20 Line Matrix printer is a higher function replacement for the IBM 6408 family, offering broadened function. The IBM 6400 series of printers are specifically designed for high- volume printing environments. These printers are flexible and can be attached to virtually any IBM or non-IBM system. IBM M.A.Q.