[comp.sys.ibm.pc.hardware] vga, clock arch, multiple monitor questions

gsisson@beowulf.ucsd.edu (Glenn Sisson) (11/06/90)

I've a number of PC hardware related questions: VGA, clock arch, and
questions about running two monitors:

  1) What characterizes a VGA board.  Are the following correct?
       - 640x480 pixels
       - 256K memory (is this max?)
       - 16 colors / palette of 256 colors
       - 17 modes (is this a superset of EGA and CGA modes?)

  2) What is the clock architecture for PC motherboards?
       - given that all boards keep track of the time, the hardware
         (and firmware for updating the clock) must be on all
         motherboards, right?
       - given adapter boards with "battery backed clocks", and the
         "no slot" clock that I've seen, do these devices merely
         update the register on the motherboard with the right time,
         or something more?
       - what is the basic relationship between the motherboard
         functionality and that of add-on battery backed clocks.

   3) Running two monitors
        - can you run one color graphics monitor and a serarate "IBM
          monochrome" monitor simultaneously using two cards (both
          displays being on at the same time)?  Don't they share the
          same memory for mapping to the displays?
        - What is the preferred method of achieving two displays, one
          for text and one for graphics?
        - Does a 386 provide any added benifits in this area at all?
          (I suppose that you could hook up a terminal to a com port
          and run a terminal emulator, but that is not what I mean)

Thanks much for any help,
--- glenn