        *****************************************
        * CENTurbo 2  HARDWARE PROGRAMMING BOOK *
        *                                       *
        * Rev 1.0 - March 2000 - Rodolphe Czuba *
        *****************************************
       
Try to use this file without printing it on paper !       
Remember that paper is from the trees !!
  

There is now 4 revisions of the CT2 :
Rev A  - The first one with up to 32 MB of ram at $04x.
Rev B  - The last one with up to 128 MB of ram at $04x.
Rev AN - The Rev A with ram at $01x.
Rev BN - The Rev B with ram at $01x.

1- WHY THE N RELEASE ?
When I designed the CT2, I needed logic space in my chips and a decoding of
$04 to $07 was so more easy to do than a decoding at $01 to $04. It's only a 
frontier question... I did that because the software developer of the set up
proposed me to use the PMMU of the 030 to remap the add $04x to $01x 
because some bad coded programs refuse to run at $04x (don't ask me why).
Even if it is working with the PPMU, we discovered later that some programs 
like OUTSIDE, MAGIC, LINIX original booter and other modify the PMMU tree in 
the memory WITHOUT check its state, assuming it is the atari original tree !
The crash is immediate because the new PMMU tree don't declare Fast-ram to 
$04x, but $01x. 
Finally, because of those stupid software, we have to not use the PMMU for 
the CT2. But keep in mind that in modern sytems, any user program can touch 
the PMMU tree what is reserved to system actions only ! But you are on 
atari...

2- HOW TO DETECT THE REVISION OF THE CT2 ?

- Is it a Rev A or B ?
  The FLASH space is shadowed at $F5000000-$F5FFFFFF.
  This feature is only implemented on Rev A/AN.
  Test this zone to identify the CT2 revision (A or B) :
  A if Flash shadow
  B if BUS ERROR  

- Is it a N hardware release ?

  A or B if no BUS ERROR when you read at $0F000000   
  AN or BN  if BUS ERROR when you read at $OF000000
   
  
      --------------------------------------------------------
      CENTurbo 2 Rev A/B/AN/BN - 32-Bit PHYSICAL ADDRESSES MAP
      --------------------------------------------------------
                      Rev 4.0 - March 2000
                       (c) Rodolphe Czuba
                        
-------------------------------------------------------------------
$00000000-$00DFFFFF | ST-RAM			 (14 MB) |
$00E00000-$00EFFFFF | TOS 4.0x ROM		  (1 MB) |
$00F00000-$00F0FFFF | I/O (IDE)			 (64 KB) |  24-Bit
$00F10000-$00F9FFFF | F030 BUS SLOT		(576 KB) |  FALCON
$00FA0000-$00FBFFFF | CARTRIDGE SLOT		(128 KB) |  Space
$00FC0000-$00FDFFFF | Not used			(192 KB) |
$00FF0000-$00FFFFFF | I/O			 (64 KB) |
-------------------------------------------------------------------
$01000000-$02FFFFFF | 32-Bit FAST-Ram (Rev AN/BN)(32 MB) |  
$03000000-$08FFFFFF | 32-Bit FAST-Ram (Rev BN)	 (96 MB) |
---------------------------------------------------------|
$04000000-$05FFFFFF | 32-Bit FAST-Ram (Rev A/B)  (32 MB) |
$06000000-$0BFFFFFF | 32-Bit FAST-Ram (Rev B)    (96 MB) |
---------------------------------------------------------|
$0C000000-$7FFFFFFF | Reserved	       	       (1856 MB) |  32-Bit
---------------------------------------------------------|  CT2
$80000000-$EFFFFFFF | Not used - Do not use    (1792 MB) |  Space
---------------------------------------------------------|
$F0000000-$F3FFFFFF | 32-Bit EXP. SLOT (Rev A)   (64 MB) |
$F4000000-$F4FFFFFF | BOOT FLASH 		 (16 MB) |
$F6000000-$F6FFFFFF | CT2 SET UP REGISTERS       (16 MB) |
$F7000000-$F7FFFFFF | FAST-Ram Controller (Rev A)(16 MB) |
$F8000000-$FEFFFFFF | Reserved                  (112 MB) |
$FF000000-$FFFFFFFF | FALCON 24-Bit SHADOW       (16 MB) |
-------------------------------------------------------------------


--------------------------------------------------------------
Rev A/B/AN/BN SET UP REGISTERS = $F6xxxxxx - BYTE WRITE access
--------------------------------------------------------------
ADD	NAME	FUNCTION (if set to 1)		REVISION

A18	FLH	FLasH WRITE ENABLE		B/BN
A19	E32	External Clock at 32 MHz 	A/AN
A20     ECO	External Clock OFF      	A/B/AN
A21	YAM	WS on YAMaha (Turbo only)	A/B/AN/BN
A22     DSP     WS on DSP    (Turbo only)	A/B/AN/BN
A23	CT2	BOOT on F030 (Turbo only)	A/B/AN/BN
--------------------------------------------------------------
1- A RESET INSTRUCTION or HARDWARE RESET sets all bits to 0.
2- Bit ECO is not recommended on Rev B. Don't use it !
3- Bit E32 : 0 = 36 MHz / 1 = 32 MHz. Rev B as only 32 MHz.
4- FLH,E32 & ECO are available in NORMAL mode too !
 

 