The following is a list of system options for the MicroPDP-11/83, 11/73, 11/53, and 11/23. The options and all ordering details are completely described in the Options and Disks and Tapes chapters. KEF11-AA Floating-point chip (11/23) HP Keyboard f. HP2392A, German Layout Commercial Instruction Set chip (11/23) HP Keyboard f. HP2392A, German Layout Floating-point processor (11/23) HP Keyboard f. HP2392A, German Layout 256-Kbyte MOS memory (11/73, 11/53, 11/23) MSV11-PK 256-Kbyte parity memory (11/53, 11/23) HP Keyboard f. HP2392A, German Layout 512-Kbyte parity memory (11/73, 11/53, 11/23) HP Keyboard f. HP2392A, German Layout- MA * 512-Kbyte MOS memory MSV11 - MB * 1-Mbyte MOS memory MSV11-QA 1-Mbyte MOS memory (11/73, 11/53, 11/23) HP Keyboard f. HP2392A, German Layout 2-Mbyte MOS memory (11/73, 11/53, 11/23) MSV11-QC 4-Mbyte MOS memory (11/73, 11/53, 11/23) MSV11-JD 1-Mbyte PMI ECC MOS memory (11/83) MSV11-JE 2-Mbyte PMI ECC MOS memory (11/83)