Esquemas de la GAMEBOY

Esto es una transcripción de la página de Jeff Frohwein, me gustaron tanto los esquemas y me apasiona tanto la gameboy que al final me decidí por tenerlos.

Trabajo pendiente de terminar!!!!

Esquemas originales GB/cartucho.

Esquema Gameboy.

This is the older, full-size GameBoy main board.

Esquema de la pantalla LCD.

This is the schematic for the separate LCD board in the older, full-size GameBoy.

Esquema de la fuente y el cartucho.

This is a schematic of the switching power supply onboard the older, full-size GameBoy as well as the two external power supplies available from Nintendo. An example EPROM cartridge is also here.

Esquema de la SuperGameboy.

When I saw Super GameBoy's on sale at the local store, I though, "Do I need this?" The longer I though about this the more my curiosity of what might possibly be inside seemed to take over my whole thinking process. I reached the point of 'no return'. I had to buy it relieve my curiosity. What I discovered inside is basically that it seems that the Super GameBoy is a regular GameBoy minus some parts (i.e., LCD, keys, power supply). An extra chip is added to interface the GameBoy to the SNES to control key inputs and to capture video to display.

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Información sobre los cartuchos.

Cartridge information on ROM-only & ROM/RAM cartridges. Provided courtesy of Pascal Felber.

Mostrar/Ocultar

Esquema de cartucho con ROM+RAM+MBC1

Now all but one pin is defined on the MBC1. Here is the 8 pin 134a chip found in MBC5 carts that contain RAM. It appears to be the same as the 26a chip found in MBC1 carts with RAM.

Circuito equivalente al MBC1

For connecting an eprom larger than 256KBits to GameBoy you need a Nintendo MBC chip or you can use this circuit.

Relacionado con el GameLink

Four-Player Adapter / Game Link Cable / Cable Adapter Schematic

Allows 4 GBs to connect together for multi-player games that support it.

GameBoy - to - Parallel Port Cable, Rev G

Diode added. Diode is needed by some PC ports. Up until now this cable has only worked on some computers due to a design bug (Thnx go to Scott Kroeger for finding it. :) It *should* now work on most computers. Here's a schematic for connecting your GameBoy to an IBM-PC Parallel Port for exchanging data. NOTE: ONLY GB BASIC CURRENTLY MAKES USE OF THIS CABLE.

GameBoy Link Port Output Format

Here's assembly code, a timing diagram, and a circuit for controlling external projects with a GameBoy. You can add as many digital outputs as you want to this port.

GameBoy Link Port I/O

Here's a circuit for controlling 16 digital outputs & reading 16 digital inputs with a GameBoy.

Adding a Game Link to a Super GameBoy

Adding a Link Port to Super Gameboy - Joshua Neal (V.1 10/16/1999)
-----------------------------------------------------------------------------

Warning: This is the documentation of the my own project.  There is the
potential to damage your hardware, so if you attempt to do this, know what
you are doing before attempting this.  I specifically disclaim any
responsibility for injury or damages caused.

-----------------------------------------------------------------------------



THE IDEA
--------

The idea came from a web page in Japanese, so the original credit goes to
the authors of that page, Papa and Shaora, as they are the ones who figured
out that it would work.  That page is at the following URL, you may want to
check it out for the pictures:

http://www.bomber.co.jp/chaola/labo/SGB_comm/

THEORY
------

Basically the SGB-CPU in the Super Gameboy is the same as the one in the
gameboy itself, including the pinout.  This means that the hardware for
link port communications exists, it just isn't connected to anything.

Nintendo makes a Super Gameboy 2 for the famicon that has the link port.

This would have cost me a bunch of $$$, so I chose to try to add one to my
original SGB.



INSIDE THE SGB
--------------

The first task was opening the Super Gameboy.  This required a special tool
that I don't have.  After attempting futiley to remove them without that
tool, I took the game to a local used game store and asked them to open it
for me.  They thought it was strange, but they did it anyways...

Comparing the circuit board inside with the pictures on the japanese page, I
determined that the circuit board of the Famicon version of the SGB was
identical to the Super Nintendo version.  I located the three pins on the
circuit board that would have to be soldered to, on the chip marked SGB-CPU.

These pins were really tiny, so I decided I needed some soldering practice.

I found a non-working PC device with a chip that had the same pin spacing,
and practiced soldering leads to that until I felt confident enough to do it
on the SGB.

I found it worked best if I scraped the pin with a knife to remove any
coating, put a small bit of solder on the pin, then prepare the wire and
reflow the solder on the pin and stick the wire on.

SCHEMATIC
---------

The schematic on the Japanese page used only a resistor for each data line,
comparing Jeff Frohwein's GB and SGB schematics, it looked like an
additional pair of diodes and a capacitor for each data line would provide
the same protection and noise filtering as the gameboy.  I decided to include
these in my project.  The schematics are located at:

http://home.hiwaay.net/~jfrohwei/gameboy/gameboy1.gif  -- Gameboy Schematic
http://home.hiwaay.net/~jfrohwei/gameboy/sgb.gif       -- SGB Schematic

PARTS
-----

7 germanium diodes 
3 100 picofarad ceramic capacitors
3 220 ohm resistors
spool 30ga wire-wrap wire
1 gameboy link port connector (female)

I used wire-wrap wire to make all the connections, only with solder joints
instead of wire wrapping.

The japanese page shows using a link cable cut in half for the connector,
while I had one of these lying around, I used a female port from an adapter
that came with a link cable that would allow it to connect to a classic
gameboy with the larger link port size.  This was inside a nice black
connector shell, that was held together with a small screw.  Once opened,
it turned out to be possible to cut the larger connector off and have a nice
female port that would accomodate a standard link cable.

I used this connector in my project, also using the black shell, which I
epoxied inside the SGB after cutting a matching hole in the side, leaving
it such that I could still unscrew and open the connector shell.  This made
the connector sturdy, and look somewhat attractive as well.

SCHEMATIC
---------

I soldered together a point-to-point circuit for this, roughly in the shape
of the following diagram.  It might have also been possible to make a small
circuit board that fits inside the SGB.  With this circuit, operation should
be identical to that of the gameboy.

Key:

-|<-    germanium diode
-)|-    100pF ceramic capacitor
-/\/\/- 220 ohm resistor

VCC ----+--------------------+-------------------+---->|----- to link pin1
        |                    |                   |         
        +-|<-+--o     to     +-|<-+--o           +-|<-+--o 
 SGB         |        SGB         +       SGB         +    
 pin o-/\/\/-+  to    pin o-/\/\/-+ to    pin o-/\/\/-+ to 
 68          | link   69          | link  70          | link
        +-)|-+ pin5          +-)|-+ pin3         +-)|-+ pin2
        |    |               |    |              |    | 
        +->|-+               +->|-+              +->|-+ 
        |                    |                   |
GND ----+--------------------+-------------------+----------- to link pin6 

Link Port Pins (looking at external female connector)

 _____
/     \
|5 3 1|
|6 4 2|
+-----+

The VCC lead I soldered to a plated-thru hole in the SGB circuit board
near the 5v pins (27 and 58) of the snes connector. The ground lead I
soldered to a plated-thru hole in the large ground plane area.

ASSEMBLY
--------

Once I got this circuit built and connected to all the necessary pins, I
hotglued down anything that might shift around, cleaned up my soldering
mess with flux remover, and put the SGB back together, only using screws
with phillips heads instead of the original screws.

TESTING
-------

I made several picture transfers with a gameboy camera, and tested operation
of the printer, all of which worked.  I deemed the project a success!

- Joshua Neal 

Miscelanea

Sharp LH534/LH538 ROM

This is the ROM used in most all ROM+MBC1+RAM carts for GB (LH534) and the ROM used in Game & Watch Gallery 2 for GBC (LH538) among others.

Samsung KM23C16/32/64000 ROM

This is the ROM used in the Zelda DX cart.

74HC595 Equivalent Circuit

The Rewired Mac 512 Keyboard schematic contains a 74HC595. Since this may not always be easy to obtain, here is an equivalent circuit using easier to obtain parts.

GameBoy I/O Example, Rev B

Here is what I use to do I/O on a GameBoy. The main chip is an 82C55 that allows you to do digital input or output on up to 24 lines. I make space for it by killing ROM access from 7FF8 to 7FFF and putting the I/O addresses here.

Rewired Mac 512 Keyboard

GB Basic supports this external keyboard schematic that connects to the link port on the GameBoy. You can rewire any keyboard. A Mac 512 keyboard is just what I had handy. If a 74HC595 is difficult to obtain, this 74HC595 Equivalent Circuit will work just as well.

Super Smart Card Base Unit Schematic

This is the schematic for the SSC base unit that I own. I have been told about a different design base unit that doesn't contain an 8751 microcontroller, but I haven't had a chance to see one yet. This schematic is for educational value only. I do not have a copy of the code required to be burned into the 8751 in order for this circuit to work.

Super Smart Card Schematic

This is the schematic for the SSC. I drew this thing not for the intention of copying their design, but because mine has gone into lockup mode and I just am trying to do everything possible to get mine working again. It has always been kind of 'flakey' in programming correctly and now it won't program at all. I am not sure if this is a problem in the base unit, SSC, or the IBM-PC software at this time.

Referencias

Jeff Frohwein's GameBoy Tech Page

The GameBoy Project