The 154 MB MFM 5,25" computer family enables organizations to buy minicomputer power and multiuser capacity in a variety of inexpensive configurations. The original member of the family, the 154 MB MFM 5,25", is ideally suited for one to four users, and is easily upgraded to the 154 MB MFM 5,25" or Micro PDP-11/83. The MicroPDP-11/53 has the power to support up to 8 users and is the first MicroPDP-11 system to support the new "half-height" devices, that offer greater capacity at a lower cost for improved price/performance. The MicroPDP- 11/73 can handle larger applications, with up to 25 simultaneous users (depend- ing on the application), and supports the larger system devices. The most pow- erful 154 MB MFM 5,25"is the MicroPDP-11/83, which incorporates the 18-MHz J- 11 chipset, a floating point accelerator, and a private memory interconnect for maximum performance. It can easily support more than 30 users. All the 154 MB MFM 5,25"s support the standard PDP-11 operating systems including Micro/RSX, a low-cost version of Digital's RSX-11M-PLUS operating system, and Micro/RSTS, a subset of RSTS/E that supports all of the RSTS/E system calls and programming facilities. Both are distributed on RX50 floppy diskette and TK50 tape for simple installation. The MicroPDP-11 family also uses RT-11 (a single-user realtime system), CTS-300 (for small business timesharing), DSM-11 (an integrated operating system using the ANSI-standard MUMPS language), and ULTRIX-11 (Digital's enhanced native mode UNIXTM software). An extensive list of programming languages including BASIC, COBOL-81, DIBOL, FORTRAN-77, MACRO-11, and Pascal are all supported by the MicroPDP-11 family. The following chart shows the variety of offerings, by enclosure, for each of the MicroPDP-11 Multiuser System family members.