Commodore Plus/4 - Plus/4 Weaknesses

Plus/4 Weaknesses

The Plus/4 had three main shortcomings, which proved fatal: unlike the C64's VIC II, the TED had no sprite capability, which strongly limited its video game graphics capabilities. Also, its tone generator was much closer to the VIC in quality than to the C64's SID, which, again, made the Plus/4 less attractive to game developers. Finally, the lack of these capabilities made C64 software compatibility impossible. Commodore may not have believed this to be a problem, as the successful C64 was incompatible with most VIC-20 software — but the C64 had developed a large software library by 1984, and while the C64 was a significant upgrade to the VIC-20 in almost every way, the Plus/4 was not equally more capable than the C64. The TED chip also experienced poor reliability.

Another problem that kept the Plus/4 from selling was that even though the three machines (116, C16 and Plus/4) were all compatible with one another, developers tended to write programs for the lowest common denominator in a computer family. So as not to alienate buyers of the C116 and C16, which were intended to be the largest selling machines in this series, most software was designed to run in 16 kB and the extra memory on the Plus/4 was not as widely supported as it could have been. Also, most development for these machines was in the less-lucrative European markets. North American developers continued to concentrate on the booming C64 market.

Peripheral compatibility with the C64 was inconsistent. The Plus/4's serial, user, and video ports were compatible with the C64, but the Datasette port was changed, rendering previous units incompatible without third-party adapters that only became available later. This also posed a problem for the many third-party C64 printer interfaces that allowed one to connect a standard Centronics parallel printer to the Commodore serial port. Since most of these interfaces connected to the Datasette port to get +5 volts for power, they were incompatible with the Plus/4 unless the user modified the interface and risked voiding the warranty. For a computer intended to be used for productivity applications, this was a heavy weakness. Additionally, with the Plus/4, Commodore abandoned the Atari-style joystick ports used on the C64, replacing them with a proprietary mini-DIN port that was said to be less prone to emit RF interference. While this may have been seen as an advantage by the Federal Communications Commission and other regulatory agencies, end users did not share this view.

This made upgrading to the Plus/4 from the VIC-20 or C64 more expensive, since the user in many cases would have to buy new peripherals in addition to the new computer. It also made the Plus/4 less attractive to new buyers, since VIC and C64 peripherals were more plentiful and less expensive than their Plus/4 counterparts. The street price for a complete C64 system was lower than that of a comparable system based on the Plus/4. Combined with the 64's greater abilities and broader software base, most buyers opted for the older model.

The Plus/4, unlike the C64 and most other computers of its time (with the notable exception of the Coleco Adam), was equipped with ROM-resident application software (developed for Commodore by TriMicro). Unfortunately, the application suite, featuring a word processor, spreadsheet, database, and graphing, was completely inadequate for the Plus/4's originally intended market of business and professional users. Better business software packages were available for equivalently-priced systems, including the C64. Since IBM compatibles were quickly dominating the small business market, the Plus/4 had no realistic chance of breaking into that. Further dividing the market was that once the user had created data using many of the built-in software packages, the result could only be saved to a connected disk drive—much of the software did not support tape. Thus, tape-based home users, the only users who might still have been interested in the Plus/4's less-capable but built-in and instantly ready software, were shut out from the package.

Most of the developers of the Plus/4 also worked on the later Commodore 128 project, which was much more successful. The lead hardware designer Bil Herd commented directly on the Wikipedia article adding: "The TED series (Plus4) was specifically designed to not encroach on the successful C64, it was designed to sell for 49 US$ and to go head to head with the Timex/Sinclair computer line, specifically the color Timex (Spectrum?). Targeting the office more than the game market, the smallest version of the computer had a total of 9 IC’s, cheapness was the main metric as defined by Jack Tramiel. After Tramiel left Commodore, the remaining management seemed to not know what to do with the Plus/4 line which resulted in untold variations and lack of focus on the targeted market. Since most of the management at that time had only experienced the C64, they tried to market it as another C64 which was exactly what Tramiel had set out not to do."

This shortcomings of the end product were the inspiration for the C128 series as, urged on by the computer press the designers calculated that if they created a computer that was compatible with the C64 that ultimately management and marketing could not damage the C64 software base (much) in spite of how they were to take the product to market.