| Sanyo MBC-550 series | |
| Developer: | Sanyo Electric |
| Type: | Personal computer |
| Lifespan: | 1984–1988 |
| Price: | <$1000 |
| Discontinued: | 1988 |
| Unitssold: | 10,000+ |
| Os: | MS-DOS |
| Power: | 120 V AC (North American model) |
| Cpu: | Intel 8088 at 3.58 MHz |
| Memory: | 128 KB |
| Display: | RGB Color Monitor CRT 70; 640x200 with 8 colors |
| Graphics: | RGB graphics adapter |
| Sound: | Buzzer (single buzztone sound, fixed duration) |
| Input: | Keyboard |
| Connectivity: | 1 parallel port |
| Dimensions: | 380 x 112 x 360 mm |
| Predecessor: | MBC-1000 |
The MBC-550 series, also known as the MBC-550/555,[1] [2] is a series of personal computers sold by Sanyo. It was unveiled at the COMDEX/Spring '83 in April 1983 and first released to market in March 1984.[3] [4] All models in the MBC-550 series featured pizza-box-style cases and Intel 8088 microprocessors and run versions of MS-DOS. On its release in 1984, the MBC-550 was the least expensive IBM PC compatible released to date, at a price of $.[5] The MBC-550 series followed Sanyo's MBC-1000 line of CP/M computers.[6]
The MBC-550 has much better video display possibilities than the CGA card (8 colors at 640x200 resolution, vs CGA's 4 colors at 320x200 or 2 colors at 640x200). Still, it is not completely compatible with the IBM PC.
The computer lacks a standard BIOS, having only a minimal bootloader in ROM that accesses hardware directly to load a RAM-based BIOS.[7] The diskette format (FM rather than MFM) used is not completely compatible with the IBM PC, but special software on an original PC or PC/XT (but not PC/AT) 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".[8] NRI was advertised in Popular Mechanics and Popular Science throughout 1985.[9]
The MBC-550 is less PC compatible than the IBM PCjr. Its inability to use much PC software was a significant disadvantage; InfoWorld 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.[10]
Early MBC-500 machines used true Intel 8088 microprocessors. In late March 1984, Sanyo reached an agreement with Intel to manufacture the 8088 in Japan as a second source, prompted by a widespread chip shortage at the time.[11] [12] 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.
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.[13]