Commodore
The Commodore PET is a line of personal computers produced starting in 1977 by Commodore International. A single all-in-one case combines a MOS Technology 6502 microprocessor, Commodore BASIC in read-only memory, keyboard, computer monitor, and, in early models, a cassette deck.
Development of the system began in 1976 and a prototype was demonstrated at the January 1977 Consumer Electronics Show. A series of problems delayed production versions until December 1977, by which time the TRS-80 and Apple II had already begun deliveries. Byte referred to the three machines collectively as the "1977 trinity".
The PET design underwent a series of updates: more memory, better keyboard, larger screen, and other modifications. The systems were a top seller in the Canadian and United States education markets, as well as for business use in Europe.
The Amiga 500, also known as the A500, is the first low-end version of the Amiga home computer. It contains the same Motorola 68000 as the Amiga 1000, as well as the same graphics and sound coprocessors, but is in a smaller case similar to that of the Commodore 128.
Commodore announced the Amiga 500 at the January 1987 winter Consumer Electronics Show – at the same time as the high-end Amiga 2000. It was initially available in the Netherlands in April 1987, then the rest of Europe in May. In North America and the UK it was released in October 1987 with a US$699/£499 list price. It competed directly against models in the Atari ST line.
The Amiga 500 was sold in the same retail outlets as the Commodore 64, as opposed to the computer store-only Amiga 1000. It proved to be Commodore's best-selling model, particularly in Europe. Although popular with hobbyists, arguably its most widespread use was as a gaming machine, where its graphics and sound were of significant benefit.
The Commodore 16 is a home computer made by Commodore International with a 6502-compatible 7501 or 8501 CPU, released in 1984 and intended to be an entry-level computer to replace the VIC-20. A cost-reduced version, the Commodore 116, was mostly sold in Europe.
The C16 and C116 belong to the same family as the higher-end Plus/4 and are internally very similar to it (albeit with less RAM - 16 rather than 64 KB - and lacking the Plus/4's user port and Three plus one software). Software is generally compatible among all three provided it can fit within the C16's smaller RAM and does not utilize the user port on the Plus/4.
While the C16 was a failure on the US market, it enjoyed some success in certain European countries and Mexico.
The Commodore 64, also known as the C64 or the CBM 64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, 7–10 January 1982, in Las Vegas). It has been listed in the Guinness World Records as the highest-selling single computer model of all time, with independent estimates placing the number sold between 12.5 and 17 million units. This claim is in spite of the Commodore 64 having three different Kernal ROM versions, two different SID sound chip versions, a few different motherboard versions and two different cases during its lifetime. Volume production started in early 1982, marketing in August for US$595 (equivalent to $1,596 in 2020).Preceded by the Commodore VIC-20 and Commodore PET, the C64 took its name from its 64 kibibytes (65,536 bytes) of RAM. With support for multicolor sprites and a custom chip for waveform generation, the C64 could create superior visuals and audio compared to systems without such custom hardware.
The Commodore 64C designers intended the computer to have a new, wedge-shaped case within a year of release, 
but the change did not occur. In 1986, Commodore released the 64C computer, which is functionally identical to the original. The exterior design was remodeled in the sleeker style of the Commodore 128. The 64C uses new versions of the SID, VIC-II, and I/O chips being deployed. Models with the C64E board had the graphic symbols printed on the top of the keys, instead of the normal location on the front. The sound chip (SID) was changed to use the MOS 8580 chip, with the core voltage reduced from 12V to 9V. The most significant changes include different behavior in the filters and in the volume control, which result in some music/sound effects sounding differently than intended, and in digitally-sampled audio being almost inaudible, respectively (though both of these can mostly be corrected-for in software). 
The 64 KB RAM memory went from eight chips to two chips. BASIC and the KERNAL went from two 
separate chips into one 16 KB ROM chip. The PLA chip and some TTL chips were integrated into a DIL 64-pin chip. The "252535-01" PLA integrated the color RAM as well into the same chip. The smaller physical space made it impossible to put in some internal expansions like a floppy-speeder. In the United States, the 64C was often bundled with the third-party GEOS graphical user interface (GUI)-based operating system, as well as the software needed to access Quantum Link. The 1541 drive received a matching face-lift, resulting in the 1541C. Later, a smaller, sleeker 1541-II model was introduced, along with the 800 KB 3.5-inch microfloppy 1581.
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