 | |
| Developer | Research Machines Limited |
|---|---|
| Type | Personal computer |
| Release date | December 1977 |
| Discontinued | 1985 |
| Media | 5¼-inch or 8-inch floppy disk |
| Operating system | CP/M |
| CPU | Z80 at 4 MHz |
| Memory | 64 KB maximum (56 KB usable) |
| Graphics | 320×192 pixels, 2 bits per pixel (optional) |
| Successor | 480Z |
The Research Machines 380Z (often called the RML 380Z or RM 380Z) was an early 8-bit microcomputer produced by Research Machines in Oxford, England, from 1977 to 1985. [1]
The 380Z used a Z80 microprocessor (hence the name) with up to 56 KB of user RAM. [2] When fitted with an optional floppy disk drive the system ran the CP/M operating system. [3] The basic system came with a text-only monochrome video card, which could be enhanced with a 320×192 high-resolution graphics board. [4]
Aided by a British government subsidy to schools for half of the price [5] the 380Z was sold mainly to educational institutions in the United Kingdom, with some also sold to industry. In 1979 a dual 8-inch disk system with 56 KB of memory cost £3266, and a 16 KB cassette-based system cost £965 (excluding VAT). [6]
The 380Z was packaged in a large, black, 19-inch rack-mount, rectangular metal case containing the power supply, a number of printed circuit boards and the optional 5¼-inch floppy disk drives. The front panel had a pair of strong carrying handles, a keyswitch and a reset button. The keyswitch controlled power and also enabled the reset button. The keyboard was separate and came in a tough metal case.
Early versions were contained in a light blue metal case with a white front and had only a cassette interface or 8-inch floppy drives; only a small number of these were made. An optional 8-bit ASCII paper tape punch/reader was also used, as this was a common storage medium at the time - where previous use of a computer had been limited to a teletype machine connected to mainframe by telephone.
The system used a passive bus architecture with no motherboard – all electronics were contained on a number of cards interconnected by ribbon cable. The only microprocessor offered was a 4 MHz Z80A. [4]
Memory was fitted in up to four banks of RAM, each of either 4 KB (4 × 1024 bytes) or 16 KB, although not every permutation was permitted. [7] Typical configurations were 16 KB for cassette-based systems and 32, 48 or 64 KB of memory on disk-based systems. Main memory was not used by the text or graphics video cards, although memory on the video cards was bank switched into a dedicated 1.5 KB address block. [2]
The 380Z was also fitted with up to 6 KB of firmware, known as COS. [2] [7] On systems fitted with less than 64 KB of RAM the COS reserved 1 KB of system RAM, leaving the rest available to the user. On the 64 KB RAM system a total of 56 KB was available to the user, with the remainder used by COS or inaccessible because of the firmware ROM, video card, and memory-mapped I/O. [2]
COS 3.4 (see below) and earlier systems came with a basic video card providing a 40×24 text-only monochrome display. Composite video output was provided for an external monitor, and an internal RF modulator provided a separate output to drive a television set. Later systems were supplied with an enhanced video card that was software-switchable between 40×24 and 80×24 character modes and supported a number of character attributes (underline, dim, reverse-video). [8] Both card types were fitted with their own dedicated video memory.
In addition to the text-mode video card the system could be enhanced with a high-resolution graphics (HRG) board. The board was fitted with a dedicated bank of 16 KB of video memory and supported two graphics modes:
A programmable lookup table with an 8-bit output mapped the pixel value to one of 256 different colours (analogue RGB output) or intensities (composite video). In RGB mode, each palette index can configured by specifying the amount of each primary colour. Possible ranges are 0 to 7 for Red and Green, and 0 to 3 for Blue (ex: 000 generates black; 773 generates white). This arrangement is known as 8-bit color and also used on other machines like the MSX2 or Atari Falcon. [9]
Output from the graphics board was mixed with output from the text-only video card, allowing text and graphics to be easily overlaid. The graphics output only covered the top 20 lines of the text display and therefore text output could be set to use only the bottom 4 lines if overlap was not desired.
Mass storage was either via cassette tape or floppy disk (which required a disk controller card). The cassette interface operated at either 300 bit/s (CUTS standard) or 1200 bit/s. [10] COS 4.0 and later systems were not fitted with the cassette interface.
Early systems could be fitted with an optional single density floppy disk controller card that could interfaced to either internal 5¼-inch or external 8-inch floppy disk drives. Disk capacity was 80 KB per side on 5¼-inch disks and 250.25 KB per side on 8-inch disks. Double-sided disk drives were treated as two independent disks with a drive letter per side. [11] CP/M used the first 4 tracks on 5¼-inch disks and the first 3 tracks on 8-inch disks, reducing the usable capacity of a single density, single-sided 5¼-inch disk to 72 KB. [11]
Later systems (referred to as the 380Z-D) were fitted with a double density Intelligent Disc Controller (IDC), which increased disk capacity to either 180 KB (48 TPI drives) or 360 KB (96 TPI drives) per side on 5¼-inch disks and 500.5 KB per side on 8-inch disks. [12] Support for a "Winchester" hard disk drive could be provided using an intelligent Host Interface Board (HIB) that implemented a SASI interface. Hard disk systems were mainly used as file servers for networked LINK 480Z systems. [13]
The passive bus allowed a number of cards to be installed in the 380Z. All systems required:
Other cards were optional, and included: [4]
The system firmware contained only a basic monitor program, known as COS (standing for Cassette Operating System in the COS 3.4 and earlier systems [14] and Central Operating System in the later disk-only systems [15] ). The monitor could be used to load application programs, such as BASIC, from cassette or to boot the disk operating system. COS also provided a software front panel allowing the display of registers and memory, and supporting breakpoints and single-stepping of machine code.
The COS monitor was stored in either 4 KB (COS 3.4 and earlier) or 6 KB (COS 4.0 and later) of ROM; [7] in the latter case part of the ROM was bank switched. [16]
COS provided a number of basic hardware control functions, such as keyboard input, writing text to the video card and disk input/output. COS functions were called by means of the Emulator Trap (EMT) pseudo-opcode, which used the Z80 RST 30H instruction to call the EMT handler function. [15] The EMT handler read the first byte following the RST 30H instruction to determine which EMT function was being requested; all parameters were passed in registers. A call-relative pseudo-opcode was also implemented using RST 28H.
COS versions were mainly tied to the new hardware functions they supported.
The main disk operating system was CP/M, initially CP/M 1.4 and later CP/M 2.2. [17] MP/M II was used on the file server version, which supported a network of LINK 480Z computers using CP/NET.
Many standard CP/M applications were available, such as WordStar. Research Machines also produced their own assembler (ZASM), text editor (TXED) and BASIC interpreter. Brian Reffin Smith, then at the Royal College of Art in London, wrote 'Jackson', one of the first digital painting programs, which ran on the 380Z and which was distributed across UK schools.
The Apple II series is a family of home computers, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer, and launched in 1977 with the original Apple II.
The Aster CT-80 is a 1982 personal computer developed by the small Dutch company MCP, was sold in its first incarnation as a kit for hobbyists. Later it was sold ready to use. It consisted of several Eurocard PCB's with DIN 41612 connectors, and a backplane all based on a 19-inch rack configuration. It was the first commercially available Dutch personal/home computer. The Aster computer could use the software written for the popular Tandy TRS-80 computer while fixing many of the problems of that computer, but it could also run CP/M software, with a large amount of free memory Transient Program Area, (TPA) and a full 80×25 display, and it could be used as a Videotext terminal. Although the Aster was a clone of the TRS-80 Model I it was in fact more compatible with the TRS-80 Model III and ran all the software of these systems including games. It also had a built-in speaker which was compatible with such games software.
The Amstrad CPC is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the ZX Spectrum, where it successfully established itself primarily in the United Kingdom, France, Spain, and the German-speaking parts of Europe.
The TRS-80 Micro Computer System is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of Tandy Radio Shack, Z80 [microprocessor]. It is one of the earliest mass-produced and mass-marketed retail home computers.
Amstrad was a British electronics company, founded in 1968 by Alan Sugar at the age of 21. The name is a contraction of Alan Michael Sugar Trading. It was first listed on the London Stock Exchange in April 1980. During the late 1980s, Amstrad had a substantial share of the PC market in the UK. Amstrad was once a FTSE 100 Index constituent, but since 2007 has been wholly owned by Sky UK. As of 2006, Amstrad's main business was manufacturing Sky UK interactive boxes. In 2010, Sky integrated Amstrad's satellite division as part of Sky so they could make their own set-top boxes in-house.
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 with the Atari 400 and Atari 800. As the first home computer architecture with coprocessors, it has graphics and sound more advanced than most of its contemporaries. Video games were a major appeal, and first-person space combat simulator Star Raiders is considered the platform's killer app. The "Atari 8-bit family" label was not contemporaneous. Atari, Inc., used the term "Atari 800 [or 400] home computer system", often combining the model names into "Atari 400/800" or "Atari home computers".
The Big Board (1980) and Big Board II (1982) were Z80 based single-board computers designed by Jim Ferguson. They provided a complete CP/M compatible computer system on a single printed circuit board, including CPU, memory, disk drive interface, keyboard and video monitor interface. The printed circuit board was sized to match the Shugart 801 or 851 floppy drive. This allowed attachment to up to two 8 inch or 5 1/4 inch floppy disk drives. The Big Board II added a SASI interface for hard disk drives, enhancements to system speed and enhancements to the terminal interface.
The SAM Coupé is an 8-bit British home computer manufactured by Miles Gordon Technology (MGT), based in Swansea in the United Kingdom and released in December 1989.
The Apple IIc is a personal computer that was introduced by Apple Inc. shortly after the launch of the original Macintosh. It was a compact and portable version of the Apple II series of computers. The IIc featured a built-in floppy disk drive and a keyboard, and was often sold with its matching monitor. The c in the name stood for compact, referring to the fact it was a complete Apple II computer setup with a floppy drive that was squeezed into a smaller notebook-sized housing. It was compatible with a wide range of software and peripherals.
The Compukit UK101 microcomputer (1979) is a kit clone of the Ohio Scientific Superboard II single-board computer, with a few enhancements for the UK market - notably replacing the 24×24 screen display with a more useful 48×16 layout working at UK video frequencies. The video output is black and white with 256 semigraphic characters generated by a two kilobyte ROM. It has no bit-mapped graphics capability. The video is output through a UHF modulator, designed to connect to a TV set.
The Rainbow 100 is a microcomputer introduced by Digital Equipment Corporation (DEC) in 1982. This desktop unit had a monitor similar to the VT220 and a dual-CPU box with both 4 MHz Zilog Z80 and 4.81 MHz Intel 8088 CPUs. The Rainbow 100 was a triple-use machine: VT100 mode, 8-bit CP/M mode, and CP/M-86 or MS-DOS mode using the 8088. It ultimately failed to in the marketplace which became dominated by the simpler IBM PC and its clones which established the industry standard as compatibility with CP/M became less important than IBM PC compatibility. Writer David Ahl called it a disastrous foray into the personal computer market. The Rainbow was launched along with the similarly packaged DEC Professional and DECmate II which were also not successful. The failure of DEC to gain a significant foothold in the high-volume PC market would be the beginning of the end of the computer hardware industry in New England, as nearly all computer companies located there were focused on minicomputers for large organizations, from DEC to Data General, Wang, Prime, Computervision, Honeywell, and Symbolics Inc.
The Memotech MTX500 and MTX512 were a range of 8-bit Zilog Z80A based home computers released by the British company Memotech in 1983 and sold mainly in the UK, France, Germany and Scandinavia. Originally a manufacturer of memory add-ons for Sinclair machines, Memotech developed their own competing computer when it was perceived the expansion pack business would no longer be viable.
The Z-89 is a personal computer introduced in 1979 by Heathkit, but produced primarily by Zenith Data Systems (ZDS) in the early 1980s. It combined an updated version of the Heathkit H8 microcomputer and H19 terminal in a new case that also provided room for a built-in floppy disk on the right side of the display. Based on the Zilog Z80 microprocessor it is capable of running CP/M as well as Heathkit's own HDOS.
DECmate was the name of a series of PDP-8-compatible computers produced by the Digital Equipment Corporation in the late 1970s and early 1980s. All of the models used an Intersil 6100 or Harris 6120 microprocessor which emulated the 12-bit DEC PDP-8 CPU. They were text-only and used the OS/78 or OS/278 operating systems, which were extensions of OS/8 for the PDP-8. Aimed at the word processing market, they typically ran the WPS-8 word-processing program. Later models optionally had Intel 8080 or Z80 microprocessors which allowed them to run CP/M. The range was a development of the VT78 which was introduced in July 1977.
The Apple II Plus is the second model of the Apple II series of personal computers produced by Apple Computer. It was sold from June 1979 to December 1982. Approximately 380,000 II Pluses were sold during its four years in production before being replaced by the IIe in 1983.
The LINK 480Z was an 8-bit microcomputer produced by Research Machines Limited in Oxford, England, during the early 1980s.
The SMC-70 is a microcomputer that was produced by Sony and released in September 1982. The system was initially released for general office use in the United States, with the SMC-70G and SMC-70GP designed for professional video generation, for example in cable television applications, and digital video effect generation.
PolyMorphic Systems was a manufacturer of microcomputer boards and systems based on the S-100 bus. Their products included the Poly-88 and the System 8813. The company was incorporated in California in 1976 as Interactive Products Corporation d/b/a PolyMorphic Systems. It was initially based in Goleta, then Santa Barbara, California.
The P8000 is a microcomputer system developed in 1987 by the VEB Elektro-Apparate-Werke Berlin-Treptow „Friedrich Ebert“ (EAW) in the German Democratic Republic. It consisted of an 8-bit and a 16-bit microprocessor and a Winchester disk controller. It was intended as a universal programming and development system for multi-user/multi-task applications. The initial list price of the P8000 was 172,125 East German marks.
The Olivetti M20 is a Zilog Z8000 based computer designed and released by Olivetti in 1982. Although it offered good performance, it suffered from a lack of software due to its use of the Z8000 processor and custom operating system, PCOS. The company introduced the IBM PC compatible Olivetti M24 in 1983 and the M20 line was phased out.
{{cite mailing list}}: CS1 maint: numeric names: authors list (link)