tests  and  operating  practices  for  EMI  reduction. MIL-STD-1310   entitled   Shipboard   Bonding, Grounding, and Other Techniques for Electromagnetic Compatibility and Safety, is a military standard for the proper  instruction  of  bonding  straps  and  grounding cables.  It  is  the  reference  for  all  shipboard electromagnetic capability (EMC) installations. It contains drawings that depict the proper shape of and lists materials required to construct bonding straps and grounding  leads  for  shipboard  electrical/electronics installation. The  Naval  Shore  Electronics  Criteria  handbook, Electromagnetic  Radiation  Hazards,  NAVSEA  OP 3565 Volumes 1 and 2, (parts 1 and 2) (NAVELEX 0967-LP-624-6010)  has  information  on  the  reduction of  EMI  at  shorebased  facilities.  All  facets  of  grounding, shielding, and equipment bonding are contained in this highly informative handbook. The Handbook  of  Shipboard  Electromagnetic Shielding  Practices,  NAVSEA   S9407-AB-HBK-010, provides specifications for cable spacing/shielding requirements and installation procedures that will minimize the effects of electromagnetic interference (EMI)  on  electronic  equipment  installed  in  naval vessels.  It  is  intended  for  use  by  ship  designers, planning  engineers,  personnel  engaged  in  the installation of electronic equipment, overhaul and repair   shipyards,   tenders,   and   other   repair   and installation activities. SUMMARY—FUNDAMENTALS  AND OPERATIONS OF COMPUTERS This  chapter  has  introduced  you  to  computer functions,  types  of  computers  (mainframe  computers, minicomputers, and microcomputers), operational uses, modes of operation, capabilities and limitations, and   operational   requirements.   The   following information  summarizes  important  points  you  should have learned: COMPUTER  FUNCTIONS  —Computers   gather, process, store, disseminate, and display data. Data may be  gathered  manually  or  automatically  or  by  a combination of both. Once processed, it can be stored either internally in memory banks or extemally on disk or tape. Data maybe disseminated and stored, or it may be sent to a display device. MAINFRAME COMPUTERS  —Mainframe computers are large computers. Those used aboard Navy vessels are designed for ruggedness and are general-purpose,   digital   data   computers   with multiprocessing capability. They usually have operator and remote consoles and a maintenance panel/display control unit (DCU). They have specific power and cooling requirements. MINICOMPUTERS  —Minicomputers  are  mid- range  computers. They are capable of stand-alone (self-contained)  operation,  or  they  maybe  an  embedded processor in a system or other type of digital device. They  usually  have  a  control  and  maintenance  panel (CMP) or computer control panel. Like the mainframe, they have a rugged frame when used aboard ship, and they have specific power and cooling requirements. MICROCOMPUTERS  —Microcomputers  (per- sonal  computers)  are  small,  lightweight  computers. Their central processing unit is contained on a single integrated chip (IC) and the entire computer system is contained on a handful of printed circuit boards in a small compact frame or cabinet. FUNCTIONAL  OPERATION  OF  COM- PUTERS —Computers exchange data with other computers, peripherals, and subsystems through a coordinated   series   of   interrupts,   requests,   and acknowledges. The signal flow is coordinated by the operational program. INTERFACING   —Interfacing   between   the computer  and  other  systems,  subsystems,  and equipment includes cabling and associated connectors. Methods of interfacing include both parallel and serial data transfers. OPERATIONAL  USES  —Operational  uses  of computers   include   tactical   and   Naval   Tactical Command Support Systems. COMPUTER   SYSTEM   CONFIGURA- TIONS  —Each  system  must  be  configured  for operation   and   maintenance.   The   hardware   and software must be compatible and must be set up to work together. MODES OF OPERATION —Computer systems may be operated in online, offline, and battle short modes. Maintenance may be performed online if there is enough memory; otherwise it will be performed offline. Battle short mode is used when it is necessary to  run  the  system  continuously  even  though  an overtemperature condition exists. OPERATIONAL   SYSTEM   REQUIRE- MENTS —The  operational  capabilities  and  limitations can  be  controlled  at  the  equipment,  or  through switchboards, control panels, or commands to the software. Effective operation depends on adherence to 1-16