The Commodore Plus/4 was originally called
Commodore 264. It was a
personal computer introduced by
Commodore Business Machines Inc in 1984. The
Commodore 264 series was CBM's next line of computer after the
Commodore 64.
The Plus/4 (or
plussy, as it is affectionately called by its fans) got its name from the built-in software, developed by
Tri Micro. It was called
3-Plus-1, and it was intended to be a business suite, but was bad, no matter how you look at it. (E.g. the
word processor was only capable of using 99 lines.)
The plussy had 64K
RAM, 121 colors, 2 voice channels and it was equipped with
Commodore Basic V3.5. It's 99%
compatible with it's little brothers, then
C16 and the
C116.
The Plus/4 wasn't nearly as successful as the
C64. In the early years, all software companies developed 16K games only (instead of using the full 64K), so that those games could be sold for both the
C16 and the Plus/4. Because of this, quality suffered, of course. This machine sold very well in
Hungary. It was used in schools, and some companies even produced a Hungarian Plus/4 variant complete with a Hungarian keyboard. It still has a devoted
demoscene.