Task: Replace a Faulty SID Sound Chip in a Commodore 64 or 128 With a Newly Made Raspberry Pi Pico-Based SIDKick
Needed: Web browser, Commodore 64 Computer, Screwdriver
Time: 15-30 minutes
Introduction
Part of the success of the Commodore 64 was its amazing MOS 6581 SID sound chip that generated really interesting sounds for games. The SID has had a huge following over the years with many users still generating new music using the chip (e.g. the HVSC resource). Unfortunately, these chips do fail leaving a Commodore 64 with no sound or partial sound which can very frustrating. These chips are not being made and there is a limited supply making them almost as expensive (~ $75 to $100 on eBay) as a C64 itself. The good news is that there are several new alternatives such as the ArmSID that emulate the sound from the SID. I decided to try the new Raspberry Pi Pico-Based SIDKick because the price was great, and I could get it shipped from within the U.S. I will post later about other models as I purchase and try them.
The SIDKick has several nice features. It can emulate both the 6581 and later 8580 SID. It has also a configuration menu that can be launched from the Commodore. There is some flash memory that allows you to load PRG files for booting.
Instructions
Purchase the SIDKick from eBay ($25) or the American RetroShop on eBay (USA). There are several different purchase options including one you can build yourself ($20), the PWM mono ($25), and the DAC stereo version ($30). I opted for the PWM mono version because I did not think I would ever use the stereo feature. You can also order from Restore Store (EU), Retro8BITshop (EU), and Plan-Net CSS (CA). Note that the DAC version does require some extra installation details.
Installation is very simple if your SID chip is in a socket. Just remove the old SID using a chip lifter or similar and drop the new one in. No wires or soldering. Note the orientation with the USB connector pointed toward the back of the computer. There are instructions here on how to install the stereo version which does require some soldering. If your chip is soldered directly to the circuit board with no socket you will need to desolder it first which does require some skill and care. I highly recommend a desoldering iron and a hot air rework station to get the SID off without damaging the contacts and traces. Here is a great video on how to do this from Adrian’s Digital Basement. I have used this method, and it works great.
You can access the configuration menu from a Commodore BASIC prompt with the command SYS 54301. There are several options to choose from including the type of SID chip you want to emulate. You can also load up a small number of PRG files that can be booted from this menu.
Note that this will work on the C64, C64C, and C128.
Comments
None of these emulated hardware solutions can perfectly reproduce the SID. Part of the problem is that each SID sounds a bit different due to variation in the analog components that change with age. However, if you need a SID replacement and don’t want to spend upwards of $100 for an original, the SIDKick is a great option. I find it perfectly acceptable for most games.
There are several SID tune players that can be run on the Commodore to play available music. I have tried the SIDPlay64.
Here is some example stereo music from the SIDKick.
I wish an inexpensive option like this was available to replace the POKEY chip on the Atari 8-bit computers. FPGA solutions are well over $100.