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PostPosted: Fri Jul 15, 2016 10:46 pm 
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Joined: Sat Jun 27, 2009 11:05 pm
Posts: 712
Location: New Mexico, USA
Hello all,

I'm getting very conflicting information between nocash's fullsnes.txt and Anomie's memmap.txt regarding the clock rate of some of the memory regions and internal registers. It seems like nearly every clock rate is different between the two.

Conflict Example 1: fullsnes states that WRAM is accessed at 3.58MHz (Fast) while memmap states that it's accessed at 2.68MHz (Slow).
Conflict Example 2: fullsnes states that Bus-B is accessed at 2.68MHz (Slow) while memmap states that it's accessed at 3.58MHz (Fast).

From doing some additional research online it would seem that memmap.txt is actually correct and fullsnes.txt is wrong. But I've found nocash's documentation to be very reliable and his is also much more recent than Anomie's, so I'm not sure what to think. Can anyone tell me which one is correct?

nocash fullsnes wrote:
Code:
System Area (banks 00h-3Fh and 80h-BFh)
  Offset       Content                                              Speed
  0000h-1FFFh  Mirror of 7E0000h-7E1FFFh (first 8Kbyte of WRAM)     3.58MHz
  2000h-20FFh  Unused                                               2.68MHz
  2100h-21FFh  I/O Ports (B-Bus)                                    2.68MHz
  2200h-3FFFh  Unused                                               2.68MHz
  4000h-41FFh  I/O Ports (manual joypad access)                     1.78MHz
  4200h-5FFFh  I/O Ports                                            2.68MHz
  6000h-7FFFh  Expansion                                            3.58MHz
Anomie memmap wrote:
Code:
  Banks  |  Addresses  | Speed | Mapping
---------+-------------+-------+---------
 $00-$3F | $0000-$1FFF | Slow  | Address Bus A + /WRAM (mirror $7E:0000-$1FFF)
         | $2000-$20FF | Fast  | Address Bus A
         | $2100-$21FF | Fast  | Address Bus B
         | $2200-$3FFF | Fast  | Address Bus A
         | $4000-$41FF | XSlow | Internal CPU registers (see Note 1 below)
         | $4200-$43FF | Fast  | Internal CPU registers (see Note 1 below)
         | $4400-$5FFF | Fast  | Address Bus A
         | $6000-$7FFF | Slow  | Address Bus A
         | $8000-$FFFF | Slow  | Address Bus A + /CART
<...snip...>


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PostPosted: Fri Jul 15, 2016 10:48 pm 
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Joined: Sun Apr 13, 2008 11:12 am
Posts: 6277
Location: Seattle
Do you have an old version of fullsnes? The one I currently see on his web site does not have the same data as what you've posted.


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PostPosted: Fri Jul 15, 2016 11:04 pm 
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Joined: Sat Jun 27, 2009 11:05 pm
Posts: 712
Location: New Mexico, USA
Wow, you're right. That's super weird. I checked to make sure I had the latest version (1.5) before I posted. I have a saved .htm from his site that says v1.5, which is also what his website says, but the frequencies are all different now. I guess maybe he forgot to update the version number...

UPDATE: Yes, I'm pretty sure he forgot to update the version number on the .htm because the .txt format has a version of 1.6.

In any case, thanks lidnariq! Everything is matching now. :)


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