(r) this line goes to the ROM only.
(s) this line is Shared between the ROM, MMC/chip, and Nintendo
(n) this line connects to the NES cart edge only, and not the ROM
(w) this line connects to the WRAM only and nowhere else

MMC5 Chip:    (100 pin QFP) [Made by Kevin Horton (khorton@iquest.net)]
----------
Only comes in one type:  'MMC5'



                           80              51
                            |              |
                           .----------------.
                        81-|                |-50
                           |      MMC5      |
                       100-|                |-31
                           \----------------'
                            |              |
                            1              30


Pin# Function      Pin# Function      Pin# Function      Pin# Function
---- --------      ---- --------      ---- --------      ---- --------

1  - RC0 *1        26 - CHR A11 (n)   51 - PRG A6 (s)    76 - /WE (w)-all
2  - RC1 *1        27 - CHR A12 (n)   52 - PRG A7 (s)    77 - NC
3  - RC2 *1        28 - CHR A13 (n)   53 - PRG A8 (s)    78 - NC
4  - +5V           29 - NC            54 - PRG A9 (s)    79 - M2 (n)
5  - CHR A0 (s)    30 - NC            55 - PRG A10 (s)   80 - GND
6  - CHR A1 (s)    31 - CIRAM /CE (n) 56 - VCC of RAM (w)81 - NC
7  - CHR A2 (s)    32 - CIRAM A10 (n) 57 - +Vbatt        82 - NC
8  - CHR A3 (s)    33 - CHR /WR (n)   58 - PRG A11 (s)   83 - CE (w)-all
9  - CHR A4 (s)    34 - CHR /RD (s?)  59 - PRG A12 (s)   84 - CHR D0 (s)
10 - CHR A5 (s)    35 - /IRQ (n)      60 - PRG A13 (r)   85 - CHR D1 (s)
11 - CHR A6 (s)    36 - PRG D0 (s)    61 - PRG A14 (r)   86 - CHR D2 (s)
12 - CHR A7 (s)    37 - PRG D1 (s)    62 - PRG A15 (r)   87 - CHR D3 (s)
13 - CHR A8 (s)    38 - PRG D2 (s)    63 - PRG A16 (r)   88 - CHR D4 (s)
14 - CHR A9 (s)    39 - PRG D3 (s)    64 - PRG A17 (r)   89 - CHR D5 (s)
15 - CHR A10 (r)   40 - PRG D4 (s)    65 - PRG A18 (r)   90 - CHR D6 (s)
16 - CHR A11 (r)   41 - PRG D5 (s)    66 - PRG A19 (r)   91 - CHR D7 (s)
17 - CHR A12 (r)   42 - PRG D6 (s)    67 - PRG A13 (n)   92 - NC
18 - CHR A13 (r)   43 - PRG D7 (s)    68 - PRG A14 (n)   93 - NC
19 - CHR A14 (r)   44 - +5V           69 - A13 (w)-all#  94 - CHR A0 (r) *2
20 - CHR A15 (r)   45 - PRG A0 (s)    70 - A14 (w)-all   95 - CHR A1 (r) *2
21 - CHR A16 (r)   46 - PRG A1 (s)    71 - /CE (w)-0     96 - CHR A2 (r) *2
22 - CHR A17 (r)   47 - PRG A2 (s)    72 - /CE (w)-1     97 - CL3 *2
23 - CHR A18 (r)   48 - PRG A3 (s)    73 - NC            98 - SL3 *2
24 - CHR A19 (r)   49 - PRG A4 (s)    74 - PRG /CE (r)   99 - GND
25 - CHR A10 (n)   50 - PRG A5 (s)    75 - NC           100 - RC3 *1

NOTES:

#: This pins have not been confirmed, and their use has been extrapolated
by the use of adjacent pins.

*1: PINS 1,2,3 & 100. These appear to be some form of data input.  They are
un-used on this particular board (Castlevania 3), and their exact
purpose is unknown; however pin #54 of the cart connects to this extra
circuitry.  this pin only connects to the access port underneath the
NES unit, so I doubt if this was ever used in any cart.

*2: PINS 94 thru 98. These set the cart in either SL or CL mode.  I have no
clue what the diffrence between the two modes are; the cart I checked 
(Castlevania 3) was set to CL mode.  

To set to CL mode:

Connect CHR A0 from the NES to A0 on the CHR ROM.  
Connect CHR A1 from the NES to A1 on the CHR ROM.  
Connect CHR A2 from the NES to A2 on the CHR ROM.  
Connect pins 97 and 98 together.
Leave pins 94,95 & 96 floating on the MMC5


To set to SL mode:

Connect pin 94 of the MMC5 to A0 of the CHR ROM.
Connect pin 95 of the MMC5 to A1 of the CHR ROM.
Connect pin 96 of the MMC5 to A2 of the CHR ROM.
Connect pin 98 to ground.
Leave pin 97 floating.


The difference between the two modes is unknown.

