initial fce ultra 0.81 import

[fceu.git] / Documentation / tech / exp / mmc5-e.txt

========= mmc5 infomation ==========
date 1998/05/31
by goroh
translated May 31, 1998 by Sgt. Bowhack
mail goroh_kun@geocities.co.jp

5000,5004 ch1,ch2 Pulse Control
 bit CCwevvvv
    CC Duty Cycle (Positive vs. Negative)
      #0:87.5%  #1:75.0%  #2:50.0%  #3:25.0%
    w Waveform Hold (e.g. Looping)
      0: Off 1: On
    e Envelope Select
      0: Varied 1: Fixed
    < e=0 >
     vvvv Playback Rate
         #0<-fast<--->-slow--> #15
    < e=1 >
     vvvv Output Volume

5002,5006 ch1,ch2 frequency L
 bit ffffffff
5003,5007 ch1,ch2 frequency H
 bit tttttfff
  ttttt sound occurence time

Objective is to remove the continuous changing of frequency for
square wave setup and do the same to the main part of the square wave
of studying the main part of the famicom. (?- Sgt. Bowhack)

5010 ch3 synthetic voice business channel
 bit -------O
  O wave output 0:Off 1:On

5011 ch4 synthetic voice business channel 2
 bit vvvvvvvv
  vvvvvvvv wave size

5015 sound output channel
 bit ------BA
  A: ch1 output  1:enable 0:disable
  B: ch2 output  1:enable 0:disable

5100 PRG-page size Setting
 bit ------SS
    SS PRG-page size
       0: 32k 1:16k 2,3:8k
* Reset is misled the first times for about 8k (?- SB)
       
5101 CHR-page size Setting
 bit ------SS
    SS CHR-page size
       0:8k 1:4k 2:2k 3:1k

5102 W BBR-RAM Write Protect 1
 bit ------AA
5103 W BBR-RAM Write Protect 2
 bit ------BB
  (AA,BB) = (2,1) permitted to write to BBR-RAM only when crowded
*Reset write around becomes prohibited when crowded

5104 Grafix Mode Setting
 $5c00-$5fff decides how it should be used
  bit ------MM
  #00:Enable only Split Mode
  #01:Enable Split Mode & ExGrafix Mode
  #02:ExRAM Mode
  #03:ExRAM Mode & Write Protect

Consideration
 MMC5 has 2 graphic mode extensions that allow more than 256 characters
on one standard game screen.  It uses Split Mode so it can display the
specified CHR-page and scroll position seperate from ExGrafix Mode to
be able to choose a palette, and the other divides it vertically.

5105 W NameTable Setting
  bit ddccbbaa
  aa: Select VRAM at 0x2000-0x23ff
  bb: Select VRAM at 0x2400-0x27ff
  cc: Select VRAM at 0x2800-0x2bff
  dd: Select VRAM at 0x2c00-0x2fff
    #0:use VRAM 0x000-0x3ff
    #1:use VRAM 0x400-0x7ff
    #2:use ExVRAM 0x000-0x3ff
    #3:use ExNameTable(Fill Mode)

Consideration
 The name table can designate 4 kinds of this resister and be a useful
special quality for this because painting and smashing it with a
character that there is 1 sheet for the remaining sheets can generally
be used. (?-SB)

5106 W Fill Mode Setting 1
  bit vvvvvvvv
  Fill chr-table
 For whether it paints or smashes it at any non-designated character

5107 W Fill Mode Setting 2
  bit ------pp
 Whether or not it uses any non-designated palettes

5113 RAM-page for $6000-$7FFF
  bit -----p--

5114-5117 Program Bank switch
 < page_size=32k >
 $5117 [8]-[F] bit pppppp--

 < page_size=16k >
 $5115 [8]-[B] bit ppppppp-
 $5117 [C]-[F] bit ppppppp-

 < page_size=8k >
 $5114 [8][9]  bit pppppppp
 $5115 [A][B]  bit pppppppp
 $5116 [C][D]  bit pppppppp
 $5117* [E][F]  bit pppppppp

*Reset is around early, Last Page misled

5120-512b Charactor Bank switch
 < page_size=8k >
 $5120-$5127 switch to mode A
 $5128-$512b switch to mode B
 $5127 [0]-[7] modeA
 $512b [0]-[7] modeB

 < page_size=4k >
 $5120-$5127 switch to mode A
 $5128-$512b switch to mode B
 $5123 [0]-[3] modeA
 $5127 [4]-[7] modeA
 $512b [0]-[3],[4]-[7] modeB

 < page_size=2k >
 $5120-$5127 switch to mode A
 $5128-$512b switch to mode B
 $5121 [0]-[1] modeA
 $5123 [2]-[3] modeA
 $5125 [4]-[5] modeA
 $5127 [6]-[7] modeA
 $5129 [0]-[1],[4]-[5] modeB
 $512b [2]-[3],[6]-[7] modeB
 
 < page_size=1k >
 $5120-$5127 switch to mode A
 $5128-$512b switch to mode B
 $5120 [0] modeA
 $5121 [1] modeA
 $5122 [2] modeA
 $5123 [3] modeA
 $5124 [4] modeA
 $5125 [5] modeA
 $5126 [6] modeA
 $5127 [7] modeA
 $5128 [0],[4] modeB
 $5129 [1],[5] modeB
 $512a [2],[6] modeB
 $512b [3],[7] modeB

Consideration
 MMC5 has mode A ,mode B and 2 kinds of CHR-page memory resistors.
They can be used for refreshing it. (?-SB)

5130 ???
analyzing it...

5200 W Split Mode Control 1
 bit Ec-vvvvv
 For the E function 0:don't use 1:use
 c boundary's side is for using Split Mode extension of graphics
   0: left side  1: right side
 vvvvv left boundary is designated with the char. # to count places

Sample.
  5200 <- #00
    (not?) used yet
  5200 <- #82
    Used for SplitMode GFX extension from left 1-2 character
  5200 <- #c2
    Used for SplitMode GFX extension from the right side 3 chars.
  5200 <- #c0
    Used for SplitMode GFX extension on the whole screen
  5200 <- #d0
    Used for SplitMode GFX extension on the right side of the screen
  5200 <- #90
    Used for SplitMode GFX extension on the left side of the screen
    
5201 W SplitMode setup for SplitMode Ext. GFX use 1
  $2005 determines the vertical movement; it can also delay ext. gfx's
 vert. movement if necessary.  It's written 2 times in bulk in the same
 way as it would slip off a grade in $2005 (??-SB)
  
5202 W SplitMode setup for SplitMode Ext. GFX use 2
   bit --pppppp
  uses vertical division of ext. gfx CHR-page designation
  index_size=4k(0x1000byte)
In case it uses a character 0x4000-0x4fff for the ext. gfx in question
  $5202 <- 4

5203 W scanline break point
  For scanline # that it splits and wants to make it designate it in bulk

5204 WR IRQ enable/disable
 W bit I-------
  I 1:IRQ Enable 0:IRQ Disable
 R bit I-------
  I 1:Scanline Hit 0:Scanline not Hit
   $5203 is designated as scanline when arrived.

5205 WR mult input/output
5206 WR mult input/output
($5205in)*($5206in) = $5205,$5206out

5c00-5fbf ext. gfx business VRAM
 shows an attribute of every position character

  <ExGrafix Mode>
  bit PPpppppp
    PP: use character palette number
    pppppp: use background CHR-PAGE number index=4k
      #0-#3F are designations, $0000-$3FFF is CHR-data's range
    Use for extension gfx

  <Split Mode>
  SplitMode uses a Name Table for extension gfx use.
  bit pppppppp
    pppppppp: use for background char. number designation

  <ExRAM Mode>
 Used for Extension RAM

5fc0-5fff
  <ExGrafix Mode>
  (not?) used yet

  <Split Mode>
  SplitMode uses gfx's Attribute Table extension.
  PPU uses $23c0-$23ff in the same way as the Attribute Table

  <ExRAM Mode>
 Used for Extension RAM

Consideration
 5c00-5fff has 3 uses.
 Split Mode and ExGrafix Mode's VBlank is written so as to become
  crowded, it writes a 0 and becomes crowded.
 Every mode tries to go around ExRAM mode including reading but it
  writes it, is effective in bulk and #5c-#5f is the output at times
  where it is effective.