                       Proportional Memory Map
                    for the Arcadia 2001 console

                            PRELIMINARY!!

                      Last updated: Apr 12, 2008



Block# (in
Kilobytes)              Contents of that block          Comments
==========================================================================

   1    $0000-$03FF     ROM memory      First 4k of cartridge; 1st kilobyte
   2    $0400-$07FF     ROM memory      First 4k of cartridge; 2nd kilobyte
   3    $0800-$0BFF     ROM memory      First 4k of cartridge; 3rd kilobyte
   4    $0C00-$0FFF     ROM memory      First 4k of cartridge; 4th kilobyte

   5    $1000-$13FF     Wasted space    Mirror of 7th block   (1024 bytes)
   6    $1400-$17FF     Wasted space    Mirror of 7th block   (1024 bytes)
   7    $1800-$1BFF     <<  Pretty much where everything takes place!?!  >>
   8    $1C00-$1FFF     Wasted space    Mirror of 7th block   (1024 bytes)

   9    $2000-$23FF     ROM memory      Second 4k of cartridge; 1st kilobyte
  10    $2400-$27FF     ROM memory      Second 4k of cartridge; 2nd kilobyte
  11    $2800-$2BFF     ROM memory      Second 4k of cartridge; 3rd kilobyte
  12    $2C00-$2FFF     ROM memory      Second 4k of cartridge; 4th kilobyte

  13    $3000-$33FF     Wasted space    Mirror of 7th block   (1024 bytes)
  14    $3400-$37FF     Wasted space    Mirror of 7th block   (1024 bytes)
  15    $3800-$3BFF     Wasted space    Mirror of 7th block   (1024 bytes)
  16    $3C00-$3FFF     Wasted space    Mirror of 7th block   (1024 bytes)

  17    $4000-$43FF     ROM memory      Third 4k of cartridge; 1st kilobyte
  18    $4400-$47FF     ROM memory      Third 4k of cartridge; 2nd kilobyte
  19    $4800-$4BFF     ROM memory      Third 4k of cartridge; 3rd kilobyte
  20    $4C00-$4FFF     ROM memory      Third 4k of cartridge; 4th kilobyte

  21    $5000-$53FF     Wasted space    Mirror of 7th block   (1024 bytes)
  22    $5400-$57FF     Wasted space    Mirror of 7th block   (1024 bytes)
  23    $5800-$5BFF     Wasted space    Mirror of 7th block   (1024 bytes)
  24    $5C00-$5FFF     Wasted space    Mirror of 7th block   (1024 bytes)

  25    $6000-$63FF     ROM memory      Fourth 4k of cartridge; 1st kilobyte
  26    $6400-$67FF     ROM memory      Fourth 4k of cartridge; 2nd kilobyte
  27    $6800-$6BFF     ROM memory      Fourth 4k of cartridge; 3rd kilobyte
  28    $6C00-$6FFF     ROM memory      Fourth 4k of cartridge; 4th kilobyte

  29    $7000-$73FF     Wasted space    Mirror of 7th block   (1024 bytes)
  30    $7400-$77FF     Wasted space    Mirror of 7th block   (1024 bytes)
  31    $7800-$7BFF     Wasted space    Mirror of 7th block   (1024 bytes)
  32    $7C00-$7FFF     Wasted space    Mirror of 7th block   (1024 bytes)




               -----------------------------------------------
                  Putting block #7 under a microscope, and
                  splitting it into four equal 8-bit chunks
               -----------------------------------------------


First 256 bytes:              (Notice that all but the last 16 bytes is RAM)
-----------------
    $1800-$18CF        208 bytes        upper screen
    $18D0-$18EF         32 bytes        user RAM
    $18F0-$18F7          8 bytes        hardware registers (RAM over-ridden?)
    $18F8-$18FB          4 bytes        user RAM
    $18FC-$18FF          4 bytes        hardware registers (RAM over-ridden?)



Second 256 bytes:       (Note that none of this is RAM memory: all non-RAM)
------------------
 First 64 bytes:
    $1900-$1908          9 bytes        hardware registers
    $1909-$193F         55 bytes        --unmapped--

 Second 64 bytes:
    $1940-$197F         64 bytes        --unmapped--

 Third 64 bytes:
    $1980-$19BF         64 bytes        hardware registers

 Fourth 64 bytes:
    $19C0-$19F7         56 bytes        --unmapped--
    $19F8-$19FF          8 bytes        hardware registers



Third 256 bytes:              (Back to being all RAM memory; but all usable)
-----------------
    $1A00-$1ACF         208 bytes       lower screen or user RAM
    $1AD0-$1AFF          48 bytes       user RAM



Fourth 256 bytes:              (Back to being all non-RAM)
------------------
    $1B00-$1BFF         256 bytes       mirror of second sub-block, above



[end of list, for now]
