Commodore 65: A 16-bit C-64 that never was

Last Updated on March 7, 2023 by Dave Farquhar

The Commodore 65 was an ill-fated attempt to extend the Commodore 8-bit line one last time and release a hybrid 8/16-bit computer with some backward compatibility with the Commodore 64. The concept was similar to the Apple IIgs and the Nintendo Super NES. Commodore never released it.

Commodore 65 rumors

commodore 65 prototype
This is a C-65 prototype operating at a computer fair in 2009. It resembles something between an Amiga 500 and a Commodore 64 in both appearance and operation. Image credit: Thomas Conté/Flickr

In the fall of 1989, rumors started spreading that Commodore was working on the Commodore 65. It was supposed to be a 16-bit Commodore 64 with a faster CPU, more memory, and improved graphics and sound, to compete with the Apple IIgs. In theory, it could have extended the C-64 family’s life expectancy a couple more years.

The C-65 was the subject of the lead editorial in the September and October 1989 issues of Compute!’s Gazette magazine, a popular magazine at the time. Rumors also circulated online. By October 1989, Compute! was saying the 65 was dead, but it appears Commodore may not have finalized the decision quite that early.

Why a 16-bit Commodore 65?

In the mid 1980s, 16 and 32-bit computing was the next big thing, but there were two problems. 32-bit computers were expensive, and 16/32-bit hybrids only slightly less so. They also didn’t have a lot of software.

In 1986, Apple built a machine with one foot in each world. The IIgs could run older 8-bit software but had new 16-bit graphics and sound capabilities and met consumers halfway on cost, too. It was reasonably successful, selling around 1.5 million units. That was a lot of computers for Apple at the time. And with Apple’s profit margins, they didn’t need to sell as many units as Commodore did.

It made sense for Commodore to consider trying to replicate that success. The debate is how long they should have considered it.


Based on the date codes on the chips, development on the Commodore 65 started no later than 1989 and extended into 1991, if only briefly. There is some conflicting information whether Commodore shelved the C-65 sometime in 1990 or 1991.

The original C-64 hardware team was long gone by 1989, so the C-65 sported custom chips designed by Victor Andrade, Bill Gardei, and Paul Lassa. Veteran software engineer Fred Bowen worked to adapt and extend the existing Kernal (sic) and Basic to the new hardware. The chipset was mostly new, to allow new capability as well as a new, more cost efficient design. Since SID designer Bob Yannes had long since left Commodore for Ensoniq, the C-65 was to use two SID chips to permit it to exceed the 64’s sound capability while remaining compatible. By 1989, some hobbyists were adding a second SID chip to a 64 and 128 anyway, which may have given Commodore the idea.

The result was a computer with a 16-bit 6502 derivative, Commodore’s own 4510, running at 3.54 MHz, similar to the 65816 CPU in the Apple IIgs. It also had 6-voice stereo sound and capablility of displaying up to 256 colors. It had a built in 3.5-inch disk drive similar to a 1581, but not identical. Rumor had it 5.25-inch drives wouldn’t work with it, but in practice, the older drives do work with the prototypes that surfaced. It had 128 KB of RAM, expandable to 1 MB.

Problems with the Commodore 65

The biggest problem with the Commodore 65 was that it came along too late. By 1989, the Amiga had a following and was near the peak of its success as a home computer. The Amiga wasn’t as popular as Commodore wanted it to be and it took a lot longer to become successful, but the C-65 wasn’t going to do anything to help that. The Amiga’s biggest problem in 1989 was figuring out how to convince people they wanted multitasking.

Price competition with Amiga

And there wasn’t a tremendous price differential between a Commodore 64 and an Amiga 500. A 64, disk drive and monitor would set you back about $450 while a comparable Amiga 500 setup would set you back about $800. Apple had a lot more room in between its Apple II machines and its Macs to position the IIgs. The Commodore 65 would have had to sell for around $600 with a monitor, and it likely would have been difficult for Commodore to hit that price point.


There was another elephant in the room as well: compatibility. The C-65 wasn’t going to be 100% compatible with the 64. It just wasn’t possible, due to the changes in the CPU and video chip. Well-behaved software would have been fine, but there was no way to know in 1989 how much software fell into the well-behaved category and how much didn’t. Given the compatibility situation with aftermarket disk drives, it’s a safe bet a good number of popular 64 titles wouldn’t have worked on the 65. The undocumented machine-code instructions in the 6510 that were missing from the 4510 would have been problematic, and the VIC-II chip had a number of unintentional quirks and features that would have made 100% backward compatibility difficult with the VIC-III as well.

Publisher support

Commitment from software publishers also might have been difficult to come by. Most of the major games publishers were committed to the Amiga line, partly because they used Amigas to develop their titles for other platforms as well.  The same publishers created versions of their new titles for the 64 as best they could. But the big movement in the games industry in 1989 was the PC market. Publishers weren’t going to waver in that commitment. The C-65 had a lot of competition for publishers’ attention, and it’s likely there wouldn’t have been a large number of titles that took advantage of its capabilities. You’d have whatever C-64 titles would run, plus a handful of Amiga-like titles, but the PC and Amiga would have had larger numbers of new, exciting titles.

How the Commodore 65 could have succeeded

If Commodore had begun work on the C-65 in the 1984-85 timeframe and released it around the time of the 128, so it hit the market around the same time as the Apple IIgs, it might have done well. At that point in time, Amiga setups started at $1395, so Commodore could have priced the machine much higher and still had a market.

The problem was that Commodore couldn’t develop the 65 that quickly. The 128 was a rush job as it was, and any non-Amiga computer coming onto the market in 1985 or later was a stand-in anyway, something more expensive than a 64 to sell until the Amiga could hit the market, and was affordable enough to be a mass-market machine. The 128 was an oddball, but Commodore developed it in a hurry using leftover parts over the course of five months. Commodore didn’t get the 65 beyond prototype stage after a year of development.

As much as people knock the 128 for not being 100% compatible with the 64, problematic titles are exceptionally rare. Calling it compatible with 99.9% of C-64 software is being very conservative, and the 65 would have never hit that level of compatibility.

In a perfect world for the C-65, Commodore would have sold a consumer a 64 in the early 1980s, then a 65 in the mid 1980s followed by an Amiga in the late 1980s and beyond. But a better scenario for Commodore would have been selling a 64 in the early 1980s, an Amiga in the mid 1980s, and a faster Amiga in the late 1980s or early 1990s.

The Commodore 65’s value today

Commodore 65 from Grapevine Group
Buried in this Fall 1994 ad, in between refurbished 64s, Amigas and PCs, the Grapevine Group slipped in the C-65 prototypes, billing it as a “new 64 released in Europe.” Not exactly.

Commodore discontinued the 65 quietly, but the prototypes leaked out when Commodore started selling off anything it could in late 1993 to try to hold off bankruptcy. A few hundred units slipped out. The mail-order dealer Grapevine Group sold a few hundred units at prices ranging from $95 to $149. Once they realized the machines had some demand, they seemed to raise prices.

Today the Commodore 65 is the most valuable Commodore computer. There are rarer Commodore prototypes, but none capture the imagination of hobbyists like the 65. When they turn up on Ebay, they tend to sell for thousands of dollars. But from time to time other odd 65-related paraphernalia turns up, so if you can’t afford a full system, you may be able to own part of one. C-65 artifacts do tend to turn up more often than Apple I artifacts at least.

Emulation and replicas

There are a couple of efforts to emulate the C-65. It’s tricky since the existing machines aren’t all 100% compatible with each other. There is also a modern effort to build a compatible machine, called the Mega-65. Since they replicate a machine that was never officially released, it’s merely a curiosity. But it’s a lot cheaper and easier than trying to get your hands on a real C-65. So you can get a Mega-65 today and not just wonder about what might have been, but actually experience it to some degree.

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