The MBC-550 series, also known as the MBC-550/555, is a series of

personal computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

s sold by

Sanyo is a former Japanese electronics manufacturer founded in 1947 by Toshio Iue, the brother-in-law of Kōnosuke Matsushita, the founder of Matsushita Electric Industrial, now known as Panasonic. Iue left Matsushita Electric to start his own bu ...

. It was unveiled at the COMDEX/Spring '83 in April 1983 and first released to market in March 1984. All models in the MBC-550 series featured pizza-box-style cases and

Intel 8088 The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers ...

microprocessors and run versions of

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

. On its release in 1984, the MBC-550 was the least expensive

IBM PC compatible An IBM PC compatible is any personal computer that is hardware- and software-compatible with the IBM Personal Computer (IBM PC) and its subsequent models. Like the original IBM PC, an IBM PC–compatible computer uses an x86-based central p ...

released to date, at a price of . The MBC-550 series followed Sanyo's MBC-1000 line of

CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Dig ...

computers.

Specifications

The MBC-550 has much better video display possibilities than the CGA card (based on the HD46505 CRTC, providing a 3-bit RGB palette of 8 colors at resolution, vs CGA's 4 colors at or 2 colors at ). Other resolutions, like and were possible. This display was not completely compatible with the IBM PC. The computer lacks a standard

BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...

, having only a minimal

bootloader A bootloader, also spelled as boot loader or called bootstrap loader, is a computer program that is responsible for booting a computer and booting an operating system. If it also provides an interactive menu with multiple boot choices then it's o ...

in ROM that accesses hardware directly to load a RAM-based BIOS. The diskette format ( FM rather than MFM) used is not completely compatible with the

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the List of IBM Personal Computer models, IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on ...

, but special software on an original PC or PC/XT (but not

PC/AT The IBM Personal Computer AT (model 5170, abbreviated as IBM AT or PC/AT) was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 802 ...

) can read and write the diskettes, and software expecting a standard 18.2 Hz clock interrupt has to be rewritten. The MBC-550 was also the computer for NRI training. Starting by building the computer, the NRI promised you would be "qualified to service and repair virtually every major brand of computer". NRI was advertised in ''

Popular Mechanics ''Popular Mechanics'' (often abbreviated as ''PM'' or ''PopMech'') is a magazine of popular science and technology, featuring automotive, home, outdoor, electronics, science, do it yourself, and technology topics. Military topics, aviation an ...

'' and ''

Popular Science Popular science (also called pop-science or popsci) is an interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is more broad ranging. It may be written ...

'' throughout 1985. The MBC-550 is less PC compatible than the

IBM PCjr The IBM PCjr (pronounced "PC junior") was a home computer produced and marketed by IBM from March 1984 to May 1985, intended as a lower-cost variant of the IBM PC with hardware capabilities better suited for video games, in order to compete mor ...

. Its inability to use much PC software was a significant disadvantage; ''

InfoWorld ''InfoWorld'' (''IW'') is an American information technology media business. Founded in 1978, it began as a monthly magazine. In 2007, it transitioned to a Web-only publication. Its parent company is International Data Group, and its sister pu ...

'' reported in August 1985 that Sanyo "has initiated a campaign to sell off" MBC-550 inventory. The company's newer computers were, an executive claimed, 99% PC compatible. Early MBC-500 machines used true

microprocessors. In late March 1984, Sanyo reached an agreement with

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

to manufacture the 8088 in Japan as a

second source In the electronics industry, a second source is a company that is licensed to manufacture and sell components originally designed by another company (the first source). It is common for engineers and purchasers to seek components that are availab ...

, prompted by a widespread chip shortage at the time. As part of the agreement with Intel, Sanyo was not to sell their 8088 chips except as part of their Sanyo MBC-550 series computers.

Dedicated magazine

''Soft Sector'' was a magazine for people who owned Sanyo MBC-550 and 555 DOS computers. (But much of the content equally applied to most IBM clones at the time.) A typical issue includes news, reviews, how-to's, technical advice and education, tips and tricks, as well as BASIC language programs that one could type in and adapt to suit one's needs.

Models

*MBC-550 – One 5.25-inch disk drive (160 KB) *MBC-555 – Two 5.25-inch disk drives (160 KB) *MBC-550-2 – One 5.25-inch disk drive (360 KB) *MBC-555-2 – Two 5.25-inch disk drives (360 KB) *MBC-555-3 – Two 5.25-inch disk drives (1.2 MB)

References

IBM PC compatibles Computer-related introductions in 1984 Sanyo computer products {{compu-eng-stub