Are You Keeping Up With the Commodore?

The Commodore 64 was an amazing computer, for a number of reasons. It's arguably not only the best-selling home computer of all time, but the one machine that really was able to change the opinion of the masses in terms of how computers could be used. It was the perfect fusion of game machine and home computer, something that other companies during the 1980s had a hard time keeping up with.

 

The downside of all old technology is that things break. I had noticed that the sound quality produced by my Commodore 64 was distorted during some programs. A good example would be the introduction to Activision's "Ghostbusters", when it plays the theme song. Some parts were fine, but others were either extremely distorted or in extreme cases not even present. This is a classic symptom of a failing SID chip in the old Commodores. The SID chip, otherwise known as the "Sound Interface Device", is the IC responsible for producing the lush, 80's sound that the C64's were renown for. The SID was extremely advanced in terms of its ability to produce a wide range of sounds, combining both analog and digital circuitry. The downside, it that overtime, these SID chips have a tendency to fail, causing the same distorted or dropped audio that I have been experiencing on my machine. In serious cases, the chip fails completely producing no sound whatsoever. Also, unfortunately, these chips have not been produced in decades, so fully functional old-stock SID chips can fetch a handsome prince on eBay. So what is one to do if they desire to keep their beige time machine singing sweet tunes? There are some after market options which can emulate the sound of a classic SID, but they are not perfect in their emulation and they can be a bit pricey as well. While pondering this conundrum it occurred to me that I actually had another Commodore 64 that I had acquired in a lot of used and mostly broken electronics. I decided to roll the dice and do a SID swap to see if the chip from the donor machine would work.

 

The actual process of swapping chips is extremely easy. Just open up the case, locate the chip (the year range of my 2 C64s the SID chip used was a 6581, which is printed on the top of the chip.), pull the chips using a chip puller - which is essentially a large set of tweezers - plug the donor chip into the socket. You want to make sure the chip is align *exactly* as it was when you pulled it from the donor machine. Mine had a dot on the chip which made it easier to see which end should be pointed "up" in the socket. After completely the swap I turned on the 64 and loaded up "Ghostbusters" and to my infinite pleasure I was treated to the entire tune during the opening screen. I then loaded up a new Commodore 64 game called "Galencia" - yes, people are still making software for these old workhorses - and was treated to lush sound dripping with that certain je na sais pas that only a fully functional SID chip can produce. After running "SID Bench", a piece of software that tests all of the registers in the chip for functionality and sound quality, I was off to the races! Luckily, the donor machine had a functioning chip. Fixing stuff is fun!