Commodore
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.
The Commodore SX-64, also known as the Executive 64, or VIP-64 in Europe, is a portable, briefcase/suitcase-size "luggable" version of the popular Commodore 64 home computer and the first full-color portable computer.
The SX-64 features a built-in five-inch composite monitor and a built-in 1541 floppy drive. It weighs 10.5 kg (23 lb). The machine is carried by its sturdy handle, which doubles as an adjustable stand. It was announced in January 1983 and released a year later, at 995 USD (equivalent to $2,595 in 2021).
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