Since  it  is  not  practicable  to  list  all  the  possible tests  in  the  SMP,  this  discussion  is  limited  only  to channel   14   test   programs.   The   channel   14   test   pro- grams  consist  of  a  scan  generator  test  routine  and various  test  routines  that  can  be  selected  from  unit  1, 2,  or  3.  Test  routines  are  selected  from  unit  2  or  3  by using  test  number  select  keyboard  code  entries  to  the computer. The   DESIGNATOR   SELECT   switch   positions   at unit  1  select  tests  from  unit  1.  Table  1-1  lists  units  2 and  3  test  number  select  codes  and  unit  1  DESIGNA- TOR  SELECT  switch  positions  used  to  select  the  test routines. The   following   paragraphs   provide   a   synopsis   of selected  channel  14  test  programs: INITIAL  DATA  DISPLAY:  This   test   pro- vides   an   initial   data   display   to   the   A/N   display   for entering  initial  test  data  required  for  the  channel  17 end-around,   D/A   converter,   gun   data,   and   encoder tests. ADDRESS  DECODE  TEST:  This  test  out- puts  a  unique  number  to  each  unit  (1,  2,  or  3)  readout to  verify  proper  address  encoding  and  console  address decoding. NIXIE  CYCLE  TEST:  This  test  cycles  all  of units  1,  2,  and  3  NIXIE  readout  digits  from  O  to  9,  in unison,   in   a   10-second   period.   The   test   checks   the channel output  lines  and  the  readout  digital  logic. GUN  DATA  TEST:  This  testis  similar  to  the channel  17  end-around  test,  except  that  the  test  results are   displayed   on   the   A/N   display,   rather   than   on   a printout.  The  test  should  be  used  for  fault  localization, rather  than  for  fault  detection. SERVO  TESTS:  These   tests   check   out   the stiff-stick  data,  the  camera-assigned  codes,  and  the TV  sight  1  and  sight  2  servo  systems.  The  servo  sys- tems  can  be  checked  using  a  servo  gain  of  8,  4,  or  2. MEMORY  CALL-UP  TESTS:  These  tests are   used   to   monitor   up   to   12   randomly   selected   or consecutive   computer   memory   locations   and   to   dis- play  them  on  the  A/N  displays. When  the  technician  troubleshoots  with  the  aid  of the  SMP,  it  is  sometimes  useful  to  know  what  data  the computer  is  transmitting  and  receiving.  The  memory locations  of  all  active  computer  input  and  output  buf- fers  can  be  called  up  by  using  this  routine. Diagnostic  Testing  Programs Diagnostic   testing   programs   are   designed   to   iso- late  malfunctions  that  occur  in  the  internal  logic  of  the printed   circuit   boards.   When   other   types   of   failures occur,  manual  procedures  are  required,  but,  in  many cases,   the   diagnostics   provide   sufficient   information to  identify  the  fictional  area  of  the  failure. Diagnostic  testing  programs  are  useful  in  locating a  problem  in  a  piece  of  equipment  once  the  problem is  isolated  to  a  unit.  The  unit  can  be  systematically tested  with  a  printout  or  readout  provided  to  the  tech- nician  to  indicate  the  problem  area.  Some  diagnostic programs  provide  an  error-code  readout,  whereas others  provide  the  direct  location  of  suspected  faulty components. An  error-code  readout  requires  searching  an  area- code   table   to   locate   the   possible   bad   component, while  the  direct  component-location  readout  tells  the technician   where   the   problem   could   be   located.   The direct   component-location   readout   method   is   usually faster   in   producing   the   location   of   suspected   failed components. MAINTENANCE  SUPPORT DOCUMENTATION Maintenance  support  documentation  falls  into  two general  categories:  (1)  logic  diagrams  that  contain  a sequence  of  steps  to  isolate  the  faults  causing  a specific  test-  or  operation-related  fault  symptom,  and (2)  system  or  equipment  functional  flow  diagrams  that allow  the  technician  to  determine  a  sequence  of  iso- lation  steps. 1-10