A cool way to put a Raspberry Pi 3B inside your Commodore-64 case.
Pimmodore-64 uses the Keymmodore-64 keyboard interface (Pi Pico) so the keyboard is 100% functional. It's a perfect setup for running BMC64, THE Commodore emulator for the Raspberry Pi 3 (any VICE version works well too). Functionally speaking, it's like running an original C-64... or C-128, or Plus/4, or PET Graphics, or PET Business. Keyboard will reconfigure itself, allowing you to access all keys, for ANY of the emulated computers.
There is also a modified version of BMC64 made by Sergio Lagoela, able to automatically switch the Compatibility Mode according the computer being emulated, including the color of the RGB LED.
To build a Pimmodore-64, you need:
- Build a Keymmodore-64 interface first, including the RGB LED.
- A Raspberry Pi 3B o 3B+.
- A MicroSD Card.
- Any power supply greater than 6VDC, with 15 Watts minimum.
- A Step-down Power converter
- Panel Barrel connector
- Rocker switch
- 2 Joysticks connectors (male DB-9)
- Male 4-pole 3.5mm plug, male RCA and female stereo 3.5mm plug (optional for analog outputs).
- HDMI extension cable.
- 2 USB extension cables.
- A 3D Printer or a 3D Printing service.
- Dupont cables and connectors.
- Some screws.
Look for the .xlsx file for the detailed BOM.
Printing the STL Files
The pieces are designed to fit any version of the legendary "Breadbin" Commodore-64 case. It won't fit a C-64C (I don't have one to design it). The project is 100% reversible, no need to drill, make holes or even glue. It uses the same mount system designed for the original PCB board.
All pieces are easy to print with a 0.4mm nozzle and a 0.2 mm layer height. For better results, do not flip the pieces, print them as provided. The .3mf file was made for my Bambulab A1, in case you find it useful. There is no need for «Everywhere» support if you 3D Printer is able to do good «bridging» (most printers do). Just use "Normal" support and «Only from the buildplate». The only piece who need "Tree" support is the USB Ports cover, and just because of the top lock arm, not for the square holes. The Pico holder includes a little support, where the board back edge rests, just trim it before placing in.
Flashing and connecting the Keymmodore-64 interface Pi Pico, to the Pi 3B.
At my project Keymmodore-64 you can find detailed information of how to set up a Raspberry Pi Pico as C-64 keyboard interface.
Besides the cable connecting the keyboard and the RGB LED, there are also three wires from the Pico, they are used for sensing what type of computer is BMC64 emulating. With this information, the Pico can switch to the corresponding mode, avoiding the manual switch with the C= and Function Keys. As you can see, these three pins have to be connected to GPIO 9, 10 and 11 of the R-Pi 3B. This is not mandatory, if you do not connect those three pins, you can always use the manual switching, including the "PC Compatible Mode".
This autoswitch feature works only with the modified version of BMC64 made by Sergio Lagoela, it is not included in the oficial release (at least until now).
Powering the Raspberry Pi
In order to being "agnostic" to the Power Supply, this project uses a Step Down Power Converter, so you can use almost any Power Brick with more than 6V and 15 Watts, a generic 12VDC with 2A will do. Of course, you need to regulate the Converter BEFORE plug in it to the Raspberry. 5.2VDC will be OK. Don't try to use a 5VDC power supply directly, the voltage drop of the connector and switch will result in 4.9VDC or less coming into de Pi, therefore the common yellow ligthing bolt sign will appear, and video and audio stuttering will happen, even with "Raspberry Certified Power Supplies" Believe me, avoiding the Converter and using a 5VDC Power Supply is not advisable, unless you connect it directly, with no switch in between.
Remember: Do not plug your Raspberry Pi until you have regulated the Voltage output to 5.2V first!!!!
Connecting the Joysticks
Unless you have wired the joysticks ports to the Pico interface as mentioned in the Keymmodore-64 project, you can connect them to the Raspberry Pi GPIO pins.
As explained in the BMC64 website, two Atari-like joysticks are supported by the emulator. Here is the wiring according the documentation:
Connecting the analog video and audio outputs (optional)
The Raspberry Pi 3B includes analog video and stereo audio output. For that you need to wire a 4-pole 3.5mm plug, to a female RCA connector for video, and a miniplug stereo female connector for audio. BMC64 will output NTSC or PAL-B video standard, according what kind of computer are being emulated. This is optional. You can use your Pimmodore-64 only with HDMI. There is a .stl version or the frame without the analog outputs for that case.
Keep in mind, the 4-pole miniplug has this (strange) pinout:
Setting up the BMC64 Emulator
For running BMC64 with the Pi connected to the Pico, you'll need the microSD card with:
1 - The BMC64 Emulator. You can use the modified or the standard BMC64 version, however as explained before, the autoswitching Mode feature won't work in the standard version.
2 - The Kernal's ROMs.
3 - The .vkm files in order to have a fully working Keyboard matching all 8-bit emulated computers. Replace the original "positional" .vkm with the new ones,
How to popup the BMC64 Emulator Menu
For entering the BMC64 Menu you need to press F12, as explained in Keymmodore-64 project, in PC Compatible Mode (green LED), you can get F12 by pressing C= and "Minus" key. However, once you are in any Emulator Mode, you can press C= and F7 key for entering the Menu. Press Left Arrow Key to go back, or exit the Menu.
How to set up BMC64 Emulator
1 - Enter BMC64 Menu, go to "Keyboard" and and change from "Symbolic" to "Positional".
2 - If you have wired the joystick ports to the PI's GPIOs, go to "Joyport" and select GPIO Bank 1 and GPIO Bank 2 for Port 1 and Port 2 respectively. If you have wired the ports to the Pico instead, select Keyset 1 and Keyset 2 and then configure those Keysets below in the same menu.
3 - Go to GPIO and check Config is set in "#1 (Nav+Joy)".
In order to make the whole process easier, I've uploaded a complete version of Lagoela's BMC64 autoswitching version, including the ROMS and the VKM files. So you only need to setup a few things. However, I strongly recommend to read the BMC64 readme file for a good understanding of the BMC64 options.
How to test your keyboard and Joysticks.
I strongly suggest you to use the Anykey program by T-Pau. It has separate versions of programs for every 8 bit Commodore Computer. Very useful.
Manual (en español).
I've written a short manual in spanish you can find useful to print (or translate).