View source for NEO-SMA

[[File:crt_sma.jpg|right|thumb|NEO-SMA chip found in a MVS cartridge. Picture courtesy of [[http://www.mvs-scans.com MVS-Scans]].]]

Info from [[http://mamedev.org/source/src/mame/machine/neoprot.c MAME's source]]

QFP144 chip found connected to the [[P ROM]]s in [[The King of Fighters '99 - Millennium Battle]] (not all sets), [[The King of Fighters 2000]] (not all sets), [[Metal Slug 3]] (not all sets) and in [[Garou - Mark of the Wolves]] (all sets) [[cartridges]]. Bankswitches the [[68k memory map|second megabyte]] ($200000~$2FFFFF) of P ROM space and provides a 16bit pseudo random number generator.

Upon system reset, the PRN is initialized to $2345.

The chip always (?) replies $9A37 on reads.

=PRN=

16bit LSFR with taps at bits 2,3,5,6,7,11,12,15. Each read steps the register.

[[File:Smalfsr.png]]


=Bankswitching=

Bankswitching is done by unscrambling the written bank number and using a 64 entry (256 bytes) lookup table to map the P ROM into $200000~$2FFFFF.

==KOF 99==

[[File:Smabskof99.png|300px|thumb]]

*Bankswitching write at $2FFFF1
*Read chip presence at $2FE447
*PRN at $2FFFF8 and $2FFFFA

Bankswitch LUT (P2 ROM address):

{|class="wikitable"
! !!0!!1!!2!!3!!4!!5!!6!!7!!8!!9!!A!!B!!C!!D!!E!!F
|-
!0
|$000000||$100000||$200000||$300000||$3CC000||$4CC000||$3F2000||$4F2000||$407800||$507800||$40D000||$50D000||$417800||$517800||$420800||$520800
|-
!1
|$424800||$524800||$429000||$529000||$42E800||$52E800||$431800||$531800||$54D000||$551000||$567000||$592800||$588800||$581800||$599800||$594800
|-
!2
|$598000||?||?||?||?||?||?||?||?||?||?||?||?||?||?||?
|-
!3
|?||?||?||?||?||?||?||?||?||?||?||?||?||?||?||?
|}

==Garou==

*Bankswitching write at $2FFFC0
*Read chip presence at $2FE447
*PRN at $2FFFCC and $2FFFF0


"KF" chip revision:

Bank scambling=12,14,6,7,9,5

{|class="wikitable"
! !!0!!1!!2!!3!!4!!5!!6!!7!!8!!9!!A!!B!!C!!D!!E!!F
|-
!0
|$000000||$100000||$200000||$300000||$280000||$380000||$2D0000||$3D0000||$2F0000||$3F0000||$400000||$500000||$420000||$520000||$440000||$540000
|-
!1
|$498000||$598000||$4A0000||$5A0000||$4A8000||$5A8000||$4B0000||$5B0000||$4B8000||$5B8000||$4C0000||$5C0000||$4C8000||$5C8000||$4D0000||$5D0000
|-
!2
|$458000||$558000||$460000||$560000||$468000||$568000||$470000||$570000||$478000||$578000||$480000||$580000||$488000||$588000||$490000||$590000
|-
!3
|$5D0000||$5D8000||$5E0000||$5E8000||$5F0000||$5F8000||$600000||?||?||?||?||?||?||?||?||?
|}

"KE" chip revision:

Bank scambling=13,11,2,14,8,4

{|class="wikitable"
! !!0!!1!!2!!3!!4!!5!!6!!7!!8!!9!!A!!B!!C!!D!!E!!F
|-
!0
|$000000||$100000||$200000||$300000||$280000||$380000||$2D0000||$3D0000||$2C8000||$3C8000||$400000||$500000||$420000||$520000||$440000||$540000
|-
!1
|$598000||$698000||$5A0000||$6A0000||$5A8000||$6A8000||$5B0000||$6B0000||$5B8000||$6B8000||$5C0000||$6C0000||$5C8000||$6C8000||$5D0000||$6D0000
|-
!2
|$458000||$558000||$460000||$560000||$468000||$568000||$470000||$570000||$478000||$578000||$480000||$580000||$488000||$588000||$490000||$590000
|-
!3
|$5D8000||$6D8000||$5E0000||$6E0000||$5E8000||$6E8000||$6E8000||$000000||$000000||$000000||$000000||$000000||$000000||$000000||$000000||$000000
|}

==Metal Slug 3==

[[File:Smabsms3.png|300px|thumb]]

*Bankswitching write at $2FFFE5
*Read chip presence at $2FE447
*PRN at $2FFFF8 and $2FFFFA

Bankswitch LUT (P2 ROM address):

{|class="wikitable"
! !!0!!1!!2!!3!!4!!5!!6!!7!!8!!9!!A!!B!!C!!D!!E!!F
|-
!0
|$000000||$020000||$040000||$060000||$070000||$090000||$0B0000||$0D0000||$0E0000||$0F0000||$120000||$130000||$140000||$150000||$180000||$190000
|-
!1
|$1A0000||$1B0000||$1E0000||$1F0000||$200000||$210000||$240000||$250000||$260000||$270000||$2A0000||$2B0000||$2C0000||$2D0000||$300000||$310000
|-
!2
|$320000||$330000||$360000||$370000||$380000||$390000||$3C0000||$3D0000||$400000||$410000||$440000||$450000||$460000||$470000||$4A0000||$4B0000
|-
!3
|$4C0000||?||?||?||?||?||?||?||?||?||?||?||?||?||?||?
|}

==KOF 2000==

[[File:Smabskof2k.png|300px|thumb]]

*Bankswitching write at $2FFFED
*Read chip presence at $2FE447
*PRN at $2FFFD8 and $2FFFDA

Bankswitch LUT (P2 ROM address):

{|class="wikitable"
! !!0!!1!!2!!3!!4!!5!!6!!7!!8!!9!!A!!B!!C!!D!!E!!F
|-
!0
|$000000||$100000||$200000||$300000||$3F7800||$4F7800||$3FF800||$4FF800||$407800||$507800||$40F800||$50F800||$416800||$516800||$41D800||$51D800
|-
!1
|$424000||$524000||$523800||$623800||$526000||$626000||$528000||$628000||$52A000||$62A000||$52B800||$62B800||$52D000||$62D000||$52E800||$62E800
|-
!2
|$618000||$619000||$61A000||$61A800||?||?||?||?||?||?||?||?||?||?||?||?
|-
!3
|?||?||?||?||?||?||?||?||?||?||?||?||?||?||?||?
|}

[[Category:Chips]]