Commodore 64 vs VIC-20

Last Updated on October 26, 2022 by Dave Farquhar

How do you compare the Commodore 64 vs VIC-20?

The Commodore 64 and its predecessor, the VIC-20, look a lot alike, and the VIC-20’s design certainly influenced the 64. The 64 is the best selling computer model of all time, and I argue the VIC-20 was the first really successful home computer. The success of the two machines allowed Commodore to surpass Radio Shack as the sales leader in the computer industry. Yes, both Commodore and Radio Shack outsold Apple.

But even though the two machines are closely related, there are significant differences between them. It’s important to remember that in the 1980s, two years was a comparatively long time because the market was moving so fast. Plus, the VIC-20 was always supposed to be an entry-level machine. In 1982, the 64 was supposed to be fairly high-end. Let’s compare and contrast the two venerable machines.

Rarity and value

The C-64 is much more common than the VIC-20, since it was produced for more than 11 years while the VIC-20 was produced for no more than four years. Commodore made about three million VICs, versus about 10 million 64s. The VIC-20 had two minor variants. The 64 had numerous variants.

But there’s more demand for the 64, so a working 64 is usually worth more than a working VIC. You can expect to pay $30-$50 for a working VIC, and $50-$100 for a working 64. Damaged or unworking units sell for less, but as long as they have some salvageable parts, they have some value. C-64 chips are harder to come by than VIC-20 chips, because many of the chips in the VIC-20 were produced by other companies under license. You can still get a new 6502 CPU or 6522 VIA if you need to, or salvage them from a dead 1541 disk drive.

The Games

Let’s face it, there’s a pretty good chance the whole reason you’re reading this is because of the games. The 64, by virtue of being on the market for 12 years, has a much larger software library.

There were perhaps 10,000 commercial titles produced for it between 1982 and 1994 and perhaps another 10,000-20,000 that originated in magazines (whether print- or disk-based) and the public domain/shareware world. There are some illicit archives of questionable legality containing the C-64’s commercial library that are 40 gigabytes in size, or larger. Remember, the largest hard drives available in the 64’s day were around 200 megabytes, and drives of 20-40 megabytes were more common. In the 64’s heyday, there was more software available for it than any single person could ever hope to buy or use.

The VIC-20 was only on the market from late 1980 to January 1985 and sales dropped off in 1983, so its software library is much smaller. About 800 commercial titles were released for it, and perhaps another 100-200 magazine type-ins were published for it.

Games today

Both machines still have software being developed for them today. Oddly enough, the VIC-20 may have more developer support because it’s a more challenging machine to program, due to its limited resolution, less capable sound, and memory. Modern titles for both machines push them much further than anyone believed possible in the 1980s, but given the extreme limitations of the VIC-20, modern VIC-20 titles are very impressive.

It would take more than a decade just to try out every game produced for the 64, so the VIC-20’s smaller library isn’t necessarily a disadvantage.

Memory

The 64 had 64K of RAM and the VIC-20 had 5K. Neither machine could use all of its RAM at once. But even with the limitations, the 64 still had more than 10 times as much memory to work with.

The VIC’s memory was expandable, and a lot of software took advantage of it because a stock VIC was so limited. RAM expansions were a very popular product for the VIC-20. Memory expansion for the 64 was trickier and didn’t become available until 1986. Not much software used it once it became available, but they were popular with users of the GEOS alternative operating system and with BBS operators..

Graphics

The VIC’s graphics didn’t stop traffic even by 1982 standards. But no other computer had color graphics of any kind at its price point. The VIC lacked hardware sprites and didn’t have a true bitmapped graphics mode. Through software tricks, it was possible to generate graphics screens, often with a resolution of 160×160.

The 64’s VIC-II graphics chip had true bitmap graphics capabilities with a maximum resolution of 320×200, although many titles used its 160×200 mode. And the 64 had sprites, which made moving objects much easier. Programming arcade-type games was much easier with sprites.

Neither machine lent itself all that well to word processing since printers printed 80 characters per line to the VIC-20’s 22 characters and C-64’s 40. But the bigger screen and additional memory made the 64 less bad in that regard. The 64 certainly had a much better selection of word processors than the VIC.

Sound

Both machines had three voices in hardware, but the VIC had more limitations than the 64 regarding the range of each voice and the number of types of sound they could produce. Bob Yannes, who went on to found Ensoniq, designed both chips, and neither machine’s sound chip came close to what he really wanted to design. It took a while for technology to catch up with Yannes’ ambitions.

The VIC-20 had better than average sound for its day. The 64’s sound was the best on the market when it came out in 1982 and it remained the best until the Amiga and Atari ST came out in 1985. Of course, the Amiga and ST cost a lot more.

Setting them up

Connecting a 64 to a TV is different from connecting a VIC. But connecting the disk drives is the same. And most of the common C-64 commands work on a VIC too. Note if you have a rare 1540 drive, it works with a VIC but not a 64. You can modify a 1540 to work with a 64 but it decreases the value significantly. A 1541 will work on a VIC-20.

Similarities

Commodore designed both the 64 and VIC-20 to meet specific price points and to decrease in retail price rapidly. Commodore was an also-ran computer company in 1980 when founder Jack Tramiel decided to try this formula with the VIC-20, and it became a runaway bestseller, selling a million units in 1982. By 1983, the 64 was a million-seller itself.

CPU

The VIC-20 had an 8-bit MOS 6502 CPU; the 64 had the similar MOS 6510. Commodore, through its MOS subsidiary, designed and manufactured its own chips. This allowed them to tailor their designs to help meet pricing goals. Both the 64 and VIC teamed up MOS CPUs with MOS-designed sound, video and I/O chips. The only chips on the board that Commodore didn’t make were the memory chips and the inexpensive glue-logic chips. VLSI (very large scale integration) was still a good decade away.

Keyboard

Both machines sported a 66-key full-travel keyboard with alphanumeric characters and four function keys, with no numeric keypad. The keyboards were interchangeable, making it the only major internal part that was interchangeable between the two machines.

Power supply

Commodore changed the VIC-20’s power supply after the C-64’s release. Later models used the same power supply as the C-64. The early two-prong VIC-20 power supply is rather reliable, since it’s little more than an AC transformer. The later VIC-20 and C-64 power supplies with a DIN connector aren’t very reliable and should be replaced before giving the machines extensive use.

Software

Software-wise, the two machines sported very similar system software in ROM. Both the 64 and VIC inherited Microsoft Basic. Furthermore, Commodore put the same cut-down Commodore Basic v2 in both machines to save costs. The kernal (someone at Commodore couldn’t spell) in both machines was adapted from the earlier Commodore PET.

It wasn’t hard to program one machine if you knew how to program the other, but the two machines weren’t compatible. The concept of device drivers was still far off, so only the simplest of programs could run on both machines unmodified.

Peripherals

And since Commodore expected a lot of VIC-20 owners to eventually upgrade to the 64, the 64 was compatible with most VIC-20 peripherals. The VIC-1515 printer and VIC-1540 disk drive didn’t work with the 64, but Commodore revised them quickly. Both machines had a user port that allowed you to connect a modem, but by the time telecommunications took off, the VIC-20’s best days were behind it. And both machines had 9-pin Atari-compatible joystick ports so they could use an Atari-compatible joysticks and paddles. The VIC only had a single port, though, while the C-64 had two.

Programming

Both the Commodore 64 and VIC-20 had the same Commodore Basic v2. This made programming graphics and sound difficult since you had to use a lot of PEEK and POKE statements to address hardware directly. A lot of users of both machines got software by typing in Basic programs printed in monthly magazines and even books. Modifying these programs to change behavior or add capabilities was a rite of passage for a lot of Commodore owners.

Other programming languages were available, particularly for the 64, but most commercial software for both machines was coded in 6502 assembly language.

Longevity

Commodore designed both machines for a three-year shelf life. Commodore got it about right with the VIC-20. But the 64 endured 12 years on the market. Commodore stopped producing chips for the 64 in 1992, but continued to sell units cobbled together from refurbished and unsold parts until they went out of business in early 1994.

The two machines do look a lot alike. Commodore designed the VIC to be as small as possible for the time. Since the 64 was a bit of a rush job, the 64’s case is just a VIC-20 case with a few minor modifications. The 64 is a darker color than the VIC. The 64 is a gray-tan beige, while the VIC is almost white. In 1986, Commodore put the 64 in a lower profile case and changed the color to a lighter beige.

Commodore 64 vs VIC-20: In conclusion

By modern standards, the Commodore 64 and VIC-20 are very similar. They had compatible CPUs and essentially the same operating system. Today we routinely swap in better graphics and sound and add memory. But in the 1980s, 1 MHz computers didn’t have enough power or memory to perform the hardware abstraction and use device drivers like we do today. So things we consider incremental improvements today were major changes then.

So that’s Commodore 64 vs VIC-20, in a nutshell.