Nintendo colour inversion
-------------------------
Note that this has to be made for each colour, this circuit only inverts one
----
Ground Blue in +5v Blue out
| ---- | |
| | | |
| | | |
| / | |
| \1K | |
| / | |
| | | |
| | | |
---\/\/\/----------- | |
| 470 | | | |
| / | | |
| \30K =22pF | |
| / | | |
| | | | |
---\/\/\/-------------\/\/\/----- |
| 10K | 56K | |
| | | |
| |b | |
| ----- Q1 | |
| e / \ c | |
---||------ -------\/\/\/----- |
| 220pF | | 3K | |
| | / | |
| | \ 100 | |
------ | / | |
---\/|/\/-- | | |
| 1K-vr | | |
| |b | |
| ----- Q2 | |
| e / \ c | |
---\/\/\/--- --------------- |
330 | |
----\/\/\/-----------------------
51
All the resistors are 1/4W, 5%
The variable resistor is 1/5W
Q1 and Q2 are both 2SC828P or Q
This transistor may be a little tricky to find, but maybe a 2N2218A
works just as well....
Nintendo inversion board pinout
-------------------------------
Negative Video In Positive Video Out
P1: 1. Green (10) P2: 1. Green
2. Red (9) 2. Red
3. Blue (12) 3. Blue
4. V Gnd (11) 4. V Gnd
5. V Gnd (11) 5. V Gnd
6. S Sync (13) 6. C Sync
(S Sync and V Gnd are just normal sync and gnd)
Power In
P3: 1. +5 volt
2. +12 volt
3. Gnd
4. Gnd
Audio In Audio Out
P4: 1. S Sound(20) P5: 1. Speaker +
2. Gnd (21) 2. Speaker -
3. Gnd (21) 3. N/C
Speaker is 8 ohm, 6W.
The Interface (Inversion) PCB inverts the colours and amplifies the
low signal sound output that comes from the main board. The above ascii
schematics illustrates how the inversion is done. Note that the sync
is (usually) just passed on through to the Interface PCB. It is already
composite active low sync when it leaves the main board. The sound can
easily be amplified with a standard TDA 2002/2003 and a couple of caps.
The numbers within brackets are pins on the main board.
It looks something like this:
-----------------------------------------
| ===== ||||| ====== --- ====== |
| P1 ||||| P3 P4 P5 |
| P2 O |
| |
| --------------------- |
| | | |
| | | |
| O O O --------------------- |
-----------------------------------------
By Martin S.
|
