Building a C64 DTV into a Gameboy Classic

I really dont remember how i got this crazy idea to build a c64 DTV into a Gameboy.
What i can remember is catching myself browsing the web to find out the dimensions
of a Gameboy Classic while holding a C64 DTV PCB in my hands. And what should i say.
It looked like a perfect fit :-D

Beeing a Commodore 64 and C64 DTV Demo programmer i already build several C64 DTV
mods for myself and for friends in the past. So i knew this new mod will be nice!

The Ingredients....: Old Gameboy Classic case, 2.5" LCD Display which wasnt used in this mod because it needs 12V
for the backlight and the gameboy only delivers 6V. C64 DTV. The Cable sticking out from under the DTV PCB is a SD2IEC
which emulates a 1541/1571/1581 Floppy Drive (No 100% emulation but single file games/demos can be loaded from it).

Here you can see the SD2IEC (Shadowolf PCB) mounted to the Gameboy cartdrige port.

The SD2IEC mounted as seen from the inside of the Gameboy. You will see in
the following pictures that i like double sided adhesive tape and HOT GLUE <3

Here i added the VCC and Ground Lines, a Power Switch and a temporary PS/2 Keyboard Connector.
The Keyboard Connector and SD2IEC was used to flash a new C64 KERNAL and Games/Demos to the DTV Flash.
The LED that is soldered to the DTV Board is part of the Voltage Converter that is used in the DTV

To have a more original look i cloaked the SD2IEC Device behind a Nintendo Tennis Cartdrige.
You can see part of the SD Card sticking out of it.

I used a lot of HOT GLUE to fix the SD2IEC Board in the module Port and some more to hold the DTV
Board in place. I had to remove the Glue in the top left Corner again in a later Step to add a
reset switch. Was just the perfect spot for it.

Here you see the Controller PCB from the Original Gameboy PCB. I cut away what i needed for the controlls,
added some vias for the ground lines, cut some traces, scraped away some Soldermask and soldered the
wires for GND, UP/DOWN/LEFT/RIGHT and the Firebuttons 1+2.

The backside of the Controller PCB. Added some more of my beloved HOT GLUE to hold some wires in place.

A lot more Soldering done here. Soldered the Wires for the SD2IEC, joystick controller board, reset switch
and a smaller connector for the optional PS/2 Keyboard. Also added the so called "Spiff Colorfix" which
fixes the broken R2R-Ladder which you find in DTV V2/V3 units. The Manufacturer swapped the resistor values
of the R2R-DAC. That means that you get only 64 out of 256 possible colors without the spiff Colorfix.
Once the resistors for the Colorfix where in place i HAD to burry tem in HOT GLUE! :D

The original Commodore 64 got only 1 Firebutton for each Joyport. In the C64 DTV it's a bit different.
The Unit was designed as a Commodore 64 in a Joystick which included 30 games. Those Games need more
Buttons for the included Games to be playable. So you got Firebutton 1+2 and Buttons A,B,C and D to
controll the Games. Actually i wanted this part to be a bit nicer but only came up (yet) with the idea
to add 4 microswitches where the start and select buttons are on the Gameboy. Burried them in HOT GLUE again

The A/B/C/D Buttons in place. Not pictured is a 3.5mm Stereo Jack on the lower right for external audio/video.

The "ALMOST" finished Unit running Mayhem in Monsterland. On the left Side is a 4x2 Switch for switching between
internal and external Display. Internal Display shuts off when you switch to external. I used a 2" LCD kit from
Adafruit because i could not use the 12V Screen that i originally wanted to use. Also got a 3.5" Adafruit screen
later which i wanted to build in. Unfortunately it doesnt Sync to Signals that are a bit off from 50/60Hz PAL/NTSC
like you got on the c64 and the DTV. It only works on my SAT receiver :-(

SO WHATS NEXT?

I'll order a 2.5" Display from Adafruit that seems to use the same LCD Controller as the 2" Display Kit from them.
Also need to add a small Amplifier for the internal Speaker. External audio is already working when connected to a TV.
I hope to find a nicer solution for the A/B/C/D Buttons. Maybe cut the original START/SELECT Buttons in halve and add
a new PCB for those.