                             MEMORY

Memory is not a straightforward computer feature. Normaal memory,

where computer programs run, where the OS (operating system)  and

(many) device drivers reside, is limited to 640K. The extra  2meg

or  4  meg  is used BY certain programs,  which  are  running  in

conventional (640K) memory. They have special features which can

load  large  blocks  of data  into  that  HI  (extended/expanded)

memory.  Then  as  the program works on  the  data,  it  switches

'pages'  of memory (16K blocks) from HI memory into  conventional

memory while it works on that section of data. When that  section

isn't  needed it swaps that back into HI, and gets another  peice

to  work  on. This lets you have HUGE spreadsheets  or  databases

running  yet  only  have 640K to run  the  program(s).  The  more

programs  (&  TSRs and device drivers) you load,  the  less  room

there  is in conventional memory to operate. Somewhere along  the

line  the system will lock or crash if you keep  adding  programs

into 640K.

