The Commodore 64 went through a number of revisions throughout its long life. The most outwardly visible of those revisions was the transition from the tan, boxy C-64 to the thinner, lighter-colored 64c. If you’e wondering about the Commodore 64 vs 64c, here’s what you need to know.
The C-64 was released in 1982 and was almost immediately successful, due to its price. It was the first computer with 64K of memory to sell for less than $600. Its companion the 1541 was the first disk drive to sell for less than $300. The combination for $900 was enticing, and Commodore struggled in 1982 and 1983 to keep up with demand.
In 1986, Commodore revised the design. By then, the industry had more or less standardized on light beige as the normal color for computers to be, although the exact shade still could differ between companies. Between the darker color and the boxy case, the so-called “breadbox” C-64 was looking a bit dated. The result was the 64c, a lighter-colored, lower-profile computer that was still 100% compatible with its predecessor. Commodore made another subtle change. The case badge moved from the upper left to the lower right and read “Commodore 64,” and, taking a cue from the 128, added the words “Personal Computer.”
Along with it, Commodore also released the 1541C, a beige-colored version of the venerable 1541. The color change also matched the C-128, released in 1985, so a 64c owner planning to upgrade could have matching peripherals without changing everything. In practice, I don’t know how many people worried about that.
The presence of the 128 may have helped 64c sales more than the styling change. Commodore engineer Bil Herd observed that 64 sales increased after the 128’s release just because consumers now had a more powerful machine to upgrade to that would still run all of their existing software.
In 1986, the 64c’s changes were just that, cosmetic. The motherboards inside were exactly the same as the previous year’s 64s contained.
But starting in 1987, Commodore started looking for ways to reduce the machine’s cost. The revision E motherboard, also known as the “short board,” consolidated a number of chips. Using higher-density RAM and ROM chips reduced that count to two each. Commodore also consolidated the PLA chip with several other chips. Also, Commodore replaced several of the chips with newer revisions built on the HMOS process. The most notable of these was the replacement of the 6581 SID chip with the 8580. One side effect of the revision was that a software trick used to make the 6581 play samples didn’t work as well (or at all) on the 8580. Overall the sound was slightly different as well. SID connoisseurs can tell the difference between the two models and they often have a preference for one over the other.
Commodore was careful what they changed. When developing the 128 they found that even changing the font design in ROM caused software to behave oddly.
After 1987, Commodore changed the keyboard in a subtle but visible way as well. The graphical symbols on the front of the keys moved to the top of the keys. Usually a 64c with the symbols on the front will have a revision E motherboard with an 8580 in it, or at least it probably shipped that way. Since parts could be swapped out, one has to examine a machine more closely to be certain of what parts might be inside. Very late production 64cs could vary even more widely. Late in life, Commodore was desperate for cashflow. So they assembled machines from whatever new and used parts were on hand to sell to discounters.
It’s also noteworthy that the box the 64c shipped in usually said “Commodore 64C,” but the case badge itself read “Commodore 64 Personal Computer.” At that time, “personal computer” didn’t automatically imply compatibility with MS-DOS or Windows like it does today. Or at least Commodore was trying to keep it a generic term. Tandy was fighting it, at the same time advertising its Tandy 1000 line as “PC compatible,” trying to promote an industry standard without mentioning IBM or Microsoft by name. Ultimately, Tandy won that battle.
Those words didn’t confuse anyone. Generally everyone accepted that computers from different manufacturers were incompatible with each other unless they explicitly claimed IBM compatibility. The phrase “IBM compatible” gave way to “Windows compatible” in the mid 1990s.