Added information about commodore formats

Commodore/C64S_FRZ.TXT

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+
+*** FRZ (C64s saved-session FRoZen files)
+*** Document revision: 1.3
+*** Last updated: March 11, 2004
+*** Compiler/Editor: Peter Schepers
+*** Contributors/sources: Miha Peternel
+
+  These files, similar in nature to  PC64's  .C64  files,  are  a  complete
+memory dump of the 64K RAM, color RAM, and all I/O ports and CPU registers.
+The only file which can hold FRZ files is a T64, as its  directory/filetype
+values allow for it. These files (up to C64s V2.0), when converted  to  raw
+binaries, are 66806 bytes large.
+
+       00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
+       -----------------------------------------------
+00000: 00 00 .. .. .. .. .. .. .. .. .. .. .. .. .. ..  <- Load Address
+ ...
+00000: .. .. 2F 47 00 AA B1 91 B3 00 00 00 00 00 00 FF  <- 64k main RAM
+00010: 00 00 00 40 02 00 BE 00 19 16 00 00 C9 9E 00 00
+00020: 00 00 00 00 40 02 69 00 00 00 03 00 00 01 08 2A
+00030: 3A A8 3A AA 4D C9 9E C9 9E 00 A0 BE 00 00 00 D9
+ ...
+10000: .. .. 01 01 01 01 01 01 01 01 01 01 01 01 01 01  <- Color RAM
+10010: 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
+10020: 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
+10030: 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
+ ...
+10400: .. .. F1 B0 F1 01 69 20 3A 00 00 00 00 00 00 00  <- I/O
+10410: 00 00 00 00 00 00 00 00 00 00 00 9B 37 00 00 00
+10420: 08 00 15 0F F0 00 00 00 00 00 00 00 01 02 03 04
+10430: 00 01 02 03 04 05 06 07 4C 00 00 00 00 00 00 00
+ ...
+
+  Bytes:$00000-00001: Load address (always $00 $00)
+         00002-10001: Main 64k RAM ($0000-FFFF)
+         10002-10401: Color RAM ($D800-DBFF)
+         10402-10409: CPU registers (8 bytes) in the following order:
+                       - PC (Program Counter, 2 bytes),
+                       - SP (Stack Pointer, 2 bytes),
+                       - A (Accumulator, 2 bytes)
+                       - X/Y (X and Y registers, 2 bytes)
+         1040A-10438: VIC-II ($D000, 47 bytes)
+         10439-10455: SID ($D400, 29 bytes)
+         10456-10465: CIA #1 ($DC00, 16 bytes)
+         10466-10475: CIA #2 ($DD00, 16 bytes)
+         10476-104F5: CPU Task data (128 bytes), containing:
+                       - Shadow registers
+                       - Emulation Registers
+
+  Seeing as each emulator uses its own format  for  its  "snapshot"  files,
+there is no simple conversion method to take one snapshot (i.e. a PC64 .C64
+file) and convert it to another emulator snapshot format (i.e. a  C64s  FRZ
+file). The only commonalities would be the  main  64k  RAM  and  color  RAM
+areas, whereas the rest of the file would be quite different.
+