The most valuable examples of the Commodore 64, generally speaking, are the early variants that have silver labels across the top. The silver label Commodore 64 is the earliest, most expensive example of the venerable machine.
In all, Commodore produced about 80,000 of these machines. That compares to several million of the most common variants. That alone makes them relatively rare. When you do find one, there’s a fairly good chance it’s not 100% original.
Early 64s had problems with their video, so much so that it warranted a 2½-page article in the debut issue of Compute!‘s Gazette about the problem and what Commodore was doing about it. Early revisions of the VIC-II chip would create occasional sparkle on the screen that caused it to flicker. Worse yet, the flicker could register collisions with sprites and cause a game to malfunction.
The Gazette article noted that Commodore was on its eighth revision of the VIC-II chip. This was in the summer of 1983, barely a year after Commodore introduced it.
Commodore was able to solve the glitch, but in the process, some early software stopped working. In most cases, the publisher fixed the software. The 64 went on to have a long life, selling 25 million-plus units for the next decade.
Many early silver-label owners had their machines modified to fix the glitches. That could mean replacing the VIC-II with a newer revision or even getting the whole motherboard swapped. Transactor magazine, on page 5 of its November 1984 issue, noted that dealers often just swapped boards to complete repairs more quickly. Later, they would repair the board and use that board as a replacement at a later time.
For this reason, a silver label 64 is worth more when all of the date codes on the chips indicate a date of manufacture in 1982 or early 1983. And if you find a silver-label 64 with all 1982 chips except for the VIC-II, you know you have a machine that received a replacement chip. The most interesting silver labels have one or more ceramic-encased chips in them. Most 64s have the much more common black plastic chips.
If you find a silver label Commodore 64 with a motherboard newer than Rev. C, you know someone swapped the entire board at one point (or someone swapped the label). If you want to tell the difference, the serial number should also be rather low for it to be a legitimate silver-label. Commodore didn’t use all the numbers, so there can be some six-digit silver labels out there. But the serial number should be in the low six digits if it runs into that range.
The most interesting silver label machines to a modern-day collector would have a Rev. A or Rev. B board.
Later 64s added separated composite output (what we now call s-video), so a rainbow-badged 64 is a better machine to actually use. But there are several million of those machines floating around, which is why those early machines have mystique with collectors.
I’ve heard that most of the swapped-out Rev.A boards had their socketed chips removed and were discarded. So the chances of finding a Rev.A board in a rainbow-badged 64 would seem low, but as soon as you say it can never happen, I’m sure someone will find one.
The silver label Commodore 64 isn’t the best example of the machine to use. In the 1980s and 1990s, people considered them junk. That’s one of the things that makes them more difficult to find today. But its relative scarcity makes it very interesting to collect. A completely unmodified silver-label is a prize for a collector today. But when a 64 fan just wants to play some Jumpman, they’ll reach for a rainbow label instead.