Sidekick64 is a versatile cartridge/expansion for the C64, C128, the C16/+4, and the VIC20. It uses a Raspberry Pi 3A+, 3B+ or Zero 2 (only for C64/C128/VIC20) to emulate memory expansions, sound devices (up to 8 SIDs, SFX Sound Expander, MIDI), freezer cartridges, cartridges such as Easyflash/GMOD, kernal replacements, C128 function ROMs and many more. Some functionalities can be combined with others, e.g. kernal replacement plus freezers or GeoRAM expansion. The Sidekick64 handles among others PRGs, D64, SID, MOD, YM and WAV files and also integrates tools such as Disk2EasyFlash, PSID64.

Its functionality is entirely defined by software. The connecting circuitry is quite simple and does not include any programmable ICs and is thus easy to build. A more complete list of currently implemented emulations/features includes

GeoRAM/NeoRAM-compatible memory expansion

freezer cartridges:

• Action Replay 4.x-7.x
• Final Cartridge 3(+)
• KCS Power Cartridge
• Super Snapshot V5
• Freeze Frame and Freeze Machine
• Atomic/Nordic Power (experimental, at best)

numerous (bank switching) cartridges such as:

• plain CBM80, C16/+4 and C128 cartridges
• Easyflash (with simplified EAPI support)
• GMod2 (including EEPROM for save games)
• MagicDesk/Domark/HES Australia
• Ocean Type A and B (up to 512k)
• Dinamic
• C64 Game System
• Funplay/Powerplay
• Comal80
• Epyx Fastload
• Warp Speed (C64 and C128)
• Megabit ROM (C128)
• (Super) Zaxxon
• Prophet64
• Simons Basic
• RGCD and Hucky's cartridge

C64 kernal replacement

Function ROMs on a C128

multiple SIDs and Sound Expander/FM emulation (up to 8 SIDs, e.g. to play The Tuneful 8)

simplified Datel and Sequential MIDI interface emulation with built-in SoundFont-synthesizer (slightly modified version of TinySoundFont)

audio player (MOD, YM and WAV files) with SID- and HDMI-output, supporting up to stereo 48kHz output on dual-SID setups (C64 and C128)

TED-sound and Digiblaster emulation for C16/+4 (to have all sound devices on one output)

The Sidekick20 (Sidekick64 on the VIC20):

• provides a VIC-emulation which outputs picture and sound via the Raspberry Pi's HDMI-output
• the emulated VIC incorporates the VFLI extension
• emulates a memory expansion (RAM1/2/3, BLK 1, 2, 3, 5, IO2/3)
• comes with a built-in rudimentary disk emulation (LOAD/SAVE via kernal vectors)
• runs PRGs and VIC20-cartridges stored as (multiple) PRG-files or CRT-files
• automatically determines memory settings for programs and carts (override with manual settings possible)

Sidekick64 has been tested with various PAL-machines (C64s, C128, C128D), C64 NTSC, C16/+4 (PAL, PAL-N, NTSC), VIC20 (PAL/NTSC), Ultimate64 and C64 Reloaded boards. Sidekick64 connects to the C16/+4 and the VIC20 using simple adapters.

The Sidekick64 software provides a main menu for frequently used features, programs, cartridges (either configured manually, or for the C64/C128 version created from a folder of favorites on the SD card), a configuration screen, and a file browser. The menu can be customized (entries, layout, color schemes, font, animation). It also autodetects and interoperates with a SIDKick if present. The C16/+4 version comes with two fabulous games ported to run directly off the emulated memory expansion: Alpharay and Pet's Rescue!

These production file is for the main-PCB of the Sidekick64 to be used with a Raspberry Pi 3A+ or 3B+.

(the Zero 2 works as well, but there is a smaller PCB for it)