#: 12757 S10/OS9/6809 (CoCo)
    29-Oct-91  00:13:03
Sb: #12752-#multivue
Fm: Kevin Darling 76703,4227
To: Everett Chimbidis 76370,1366

MMap is pretty straight forward.  It shows the use of the 64 (or more, if you
have a fixed mmap and more than 512K) 8K blocks in your system.  Example:

    0 1 2 3 4 5 6 7 8 9 A B C D E F
 #  = = = = = = = = = = = = = = = =
 0  U M M M M U M U M M U U M M U M   <-- boot modules and commands
 1  M M U M M M M M M M M M M M M _
 2  M _ _ _ M M _ _ _ _ _ _ _ _ _ _
 3  _ _ _ _ _ _ _ _ _ _ _ _ _ U U M   <-- video mem and kernel

They're arranged in hex layout.  The upper left is block $00, the bottom
rightmost is block $3F (63).  "M" means the block is being used for modules(s).
"U" means it's just used for data/graphics.  "." means you don't have any
memory there, and "_" means the block is free.

OS-9 loads the bootfile and commands into the lowest free block numbers. On the
CoCo-3, the uppermost blocks are allocated downward for video memory, because
graphics memory must be contiguous.

You can use the output of "dirm" or sometimes "mdir e" to check and see what
modules are in what block numbers.  The main use for "mmap" is to get a better
visual feel of where your memory blocks are going to :-)

BTW, your mmap output will probably bogusly show "U" where mine has "M"s in the
first few blocks... that's because the original CoCo L-II had to do some tricks
to allocate bootfile memory.
 

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