Sinclair ZX Spectrum
|
|
| Manufacturer | Sinclair Research , Amstrad |
| Type | Home computers |
| publication | April 23, 1982 |
| End of production | 1992 |
| Factory price | At launch: * ZX Spectrum 16 £ 125 * ZX Spectrum 48 £ 175 |
| processor | Z80A @ 3.5 MHz |
| random access memory | 16 KB or 48 KB |
| graphic | 256 × 192 pixels 15 colors |
| Sound | Via built-in loudspeaker |
| Disk | Compact Cassette , Microdrive (tape drive) |
| operating system | Sinclair BASIC |
| predecessor | Sinclair ZX81 |
| successor | Sinclair QL * ZX Spectrum Plus * ZX Spectrum 128K |
The Sinclair ZX Spectrum 16 / 48k is a home computer launched on April 23, 1982 by UK- based Sinclair Research, priced at £ 125 and £ 175, respectively. In 1986 Amstrad acquired the brand name and marketed the computer and successor models until 1992.
hardware
It was the successor to the Sinclair ZX81 . In contrast to its predecessor, it works with the ASCII character set. As processor came a Zilog Z80 (Z80A 3.5 MHz) are used. It had 16 or 48 KB of RAM and 16 KB of read-only memory (ROM). The 16k versions could later be expanded to 48k with additional RAM. A commercially available cassette recorder is connected as data storage device. Hardware expansions can be connected via a slot.
As with all Sinclair computers of that time, the structure of the computer was designed to be affordable. In particular, the number of components has been minimized, and the cheapest possible use have been made: the version with 48 KB memory, for example, used defective 64 kilobyte RAM modules in which the defective bank was hidden.
A special ("custom") chip, the ULA, takes care of the screen display, the sound output and the cassette recorder interface. In contrast to the ZX81, the ULA takes on all the tasks of image display so that the processor is not burdened with it.
The graphics resolution is 256 × 192 image points ( pixels ). For the color display, 8 × 8 pixels are combined in blocks, so that effectively only a color grid of 32 × 24 blocks is available. In each block, the foreground and background color can be selected from 8 colors. In addition, the colors of a block can be brightened or switched to flashing. The frame color can be selected separately from 8 colors. A television set is usually connected as output device via the antenna input. The expansion port is also a baseband - video signal and could be removed with external hardware and reinforced.
Screen printout of the color table with error message / status line
Representation of the same color table on a black and white television
Typeface of the ZX Spectrum with the curriculum vitae of Sir Clive Sinclair
The Spectrum offers a very limited sound output via a built-in loudspeaker; the TV audio channel is not used. In addition, the loudspeaker is very quiet, especially in the earliest models. However, there is the (unofficial) possibility of connecting external loudspeakers to the audio channel output for the cassette recorder. The loudspeaker can only be switched on and off by the processor, which must also generate the audio frequency. This blocks the sound output from the processor. In some games, however, two-part or even polyphonic music was created through tricky programming, the latter, however, of rather poor quality. The AY-3-8910 sound chip was also installed in the later 128 KB models to remedy this shortcoming.
A ROM is primarily BASIC - interpreter with integrated command prompt and operating system housed. The keyboard of the original Spectrum consists of rubber keys over a contact foil. In contrast to other computers, the BASIC commands are not typed in letter by letter. Each key is assigned up to six characters and commands, so that a key press or a key combination is sufficient for a BASIC command. This enables relatively quick and typing error-free programming. Furthermore, the BASIC interpreter can recognize the commands very quickly.
To identify the individual components, move the mouse pointer over them
and click for further information.
The overall appearance is small compared to other computers of the time. The power supply has been designed as an external device. The color of the device is black, the texture of the keyboard is reminiscent of erasers. The device heats up very strongly during operation, which affects the service life of the keyboard's contact mat.
Numerous extensions from third-party providers and a large assortment of games made the Spectrum the most successful computer from Sinclair.
software
The main software available was games, but also word processors, databases, various programming languages, assemblers and debuggers . In contemporary home computer magazines, data carriers were not yet included, but games, for example, were printed as BASIC programs ( program printouts ) and patient users could enter them using a rubber keyboard. In the same way, larger programs were accessible by typing in their own books. Compared to the dominant, slightly more expensive C64 from Commodore, the availability and diversity of the software on the German market was significantly lower, also because the ZX Spectrum was hardly present in the American market, which is why companies there usually do not use their software for offered the Spectrum. The ZX Spectrum has long been the best-selling home computer with the largest range of software in the UK market.
In some countries of the former Eastern Bloc , for example in Hungary, programs for the Spectrum, later also for the Commodore 16 and Commodore 64 , were occasionally broadcast in the form of audio signals in television and radio broadcasts that dealt with computer technology . These could be recorded with a cassette recorder and then loaded into the home computer.
Programming was mainly carried out under BASIC (as standard in ROM), assembler and Pascal . With the availability of appropriate peripheral devices, the CP / M operating system was also partially used on later models (the original Spectrum cannot run a CP / M without additional modules, since this requires RAM memory at address 0, but the Spectrum only there ROM has).
equipment
Even a minimal system consists of the computer and several peripheral devices : the associated external power supply unit (9 V DC voltage), which also supplies power to other peripheral devices (e.g. interfaces and microdrive), the manual, the Sinclair BASIC and the Handling of the device is explained in detail, as is the cassette with sample programs that demonstrate the capabilities of the computer and whose BASIC source texts provide insight into the programming options. A functioning system also requires devices that the user must already have. A standard television with antenna input is required as a monitor. When using a black and white television , the gray tones (together with the brightness level BRIGHT , 8 colors with 16 color nuances are possible) are graduated with high contrast. A cassette recorder allows the sample programs to be loaded. Unlike some other home computers, no special computer cassette recorders (" datasettes ") were offered for the ZX Spectrum. Instead, an ordinary recorder for compact cassettes was used, which only had to have microphone and headphone sockets into which the connection cable supplied with the ZX Spectrum could be plugged. It was the responsibility of the user to start and stop the tape in good time.
Although at that time no distinction was usually made between internal and external peripheral devices, internal accessories are already built into this device, e.g. B. the HF converter, which generates the television picture from the video signals, or the interface on the motherboard for connecting the cassette recorder.
Microdrive mass storage device
From 1983 the manufacturer offered tape drives with the designation ZX Microdrive . These are connected to the computer via the ZX Interface 1 controller. An endless belt runs in the plug-in modules , which is led past a tape head and offers about 85 kilobytes of storage capacity. A complete run of the belt takes 7.5 seconds. These microdrives are also used in the Sinclair QL , but there with a storage capacity of around 110 kilobytes. This storage medium is not to be confused with the Microdrives from IBM .
ZX interface 1
The ZX Interface 1 for the Spectrum was first released in 1983. It was originally intended as a local area network interface for use in schools. However, the device was redesigned before it was released and then used as a controller for up to eight ZX Microdrive drives. The device also offered an RS-232 interface to connect mainly printers. Interface 1 contained an 8K ROM. Since the spectrum had already fully occupied the entire address space , the ROM of Interface 1 was mapped into the address space of the 16K ROM using bank switching .
The interface is designed so that it can be screwed tightly to the computer to form a unit. To do this, two screws were unscrewed from the basic device and the interface was screwed tightly to the back of the computer after plugging it into the motherboard, without having to open it first. The basic device is therefore slightly inclined, similar to a keyboard that is ergonomically tilted forwards.
The device offers a network connection with which you can connect up to 64 ZX-Spectrums via network cable. This network was called ZX Net and had a data rate of up to 100 kbit / s.
Interface 1 and Microdrive were sold as a package. Also included was software, including some games and the word processing program Tasword II, in which printer and file functions were implemented in BASIC routines for better adaptation to the user's hardware. It contained its own character set that divided each standard character into two narrow characters with only 7 × 3 pixels (standard characters without descenders) and was thus the only word processing program that made the limited possibilities of the spectrum available for normal office work.
ZX interface 2
The ZX Interface 2 is a peripheral device that was first sold in September 1983. It was equipped with two joystick ports and a ROM cartridge slot , which was intended for game modules. The joystick connections were the same 9-pin D-Sub sockets adopted from the Atari 2600 as in almost all other computer and console systems at the time, but their control via software was not compatible with the widespread Kempston interface, which means that the most of the games released before the interface did not work.
The number of game cartridges published was limited: it was almost twice as expensive to manufacture as it was to sell on compact cassettes, and the storage space on the modules was limited to 16 KB, even though the Spectrum had a memory of 48 KB.
Ten games were released:
- JetPac
- PSSST
- Cookie
- Tranz Am
- Chess
- backgammon
- Hungry Horace
- Horace and the Spiders
- Planetoids
- Space Raiders
Printer and other accessories
All printers suitable for the Sinclair ZX81 can be connected to the Spectrum . The inexpensive printer from Sinclair - although not intended for professional word processing - printed on aluminum-coated paper with the resolution of the screen (256 dots per line). The paper is slightly wider than the printout of a present-day receipt, which made a very compact device - about the size of a fist - possible. (for this and compatible models see description: Printer for the ZX81 )
In addition to these devices, there were a number of extensions such as joystick interfaces (e.g. ZX Interface 2 or Kempston), the Multiface 1/128 or various systems for connecting floppy drives (e.g. Beta Disk Interface) for the Sinclair ZX Spectrum. There are also craft solutions for connecting hard drives.
Successor models
.jpg)
Sinclair himself initially brought out the ZX Spectrum Plus , the electronics of which are identical to those of the 48 KB Spectrum. In contrast to this, the Spectrum Plus is built into a larger plastic housing and offers a keyboard with hard keycaps. There is also a reset button on the side. The additional key caps actuate several individual keys electrically using a well thought-out membrane keyboard under the caps, which means that some frequently used key combinations of the previous model can now be reached using individual keys. The shape and size of the housing have been selected so that original accessories for the ZX Spectrum can also be connected to the ZX Spectrum Plus.
The next model from Sinclair was the ZX Spectrum 128K. It can be switched to a compatibility mode so that almost all hardware and software of the previous ZX-Spectrum versions can be used. This computer looks similar to the ZX Spectrum Plus, but offers 128 KB of memory and a three-channel sound chip (which affects program compatibility despite compatibility mode). It also has a MIDI interface.
Then the Sinclair QL computer system (abbreviation for Quantum Leap, German quantum leap ), based on a Motorola 68008 and Intel 8049, with 128 KB RAM appeared. Two microdrives are already integrated into the housing as mass storage devices. In graphics mode, the QL can display a maximum of 512 × 256 pixels, in text mode 85 × 25 characters. The built-in networking and multitasking capabilities of the computer were particularly interesting. Unfortunately, the Sinclair QL was announced too early, which meant that the waiting time for potential customers was very long. Although the price-performance ratio was very good, the QL could not assert itself against the competition in this market segment, such as the Apple Macintosh series, because the software offered on these competing devices was significantly more advanced than the QL.
A "Super Spectrum" announced by Sinclair, which was to be called Spectrum LOKI, was intended as a Commodore-Amiga competition and should run with two Z80H processors, never got beyond the early prototype stage. The project was discontinued after Sinclair was sold to Amstrad.
Numerous clones have been built around the world, including a. from Timex in the USA, but also (without a license) from universities in the GDR such as B. the GDC1 , HCX , KuB 64K or Spectral and elsewhere.
After the manufacturer Sinclair Research had been sold to Amstrad for 5 million British pounds, the models Spectrum + 2 / + 2A (with integrated cassette recorder) and +3 (with integrated 3-inch floppy disk drive) came onto the market under their leadership which, like the Spectrum 128K, each have 128 kilobytes of memory, a MIDI interface and a three-channel sound chip; the latter was also used in the Schneider and Amstrad CPC computers. These models have two operating modes, extended and compatible with the original spectrum.
In 2017, Henrique Olifiers announced a Kickstarter campaign to fund an official and Sinclair-approved successor, the ZX Spectrum Next. 3,113 backers raised £ 723,390 and unlocked multiple perks in the process. While the motherboards were delivered after a few months, the delivery of the complete devices with the keyboard housing designed by Rick Dickson was delayed until 2020. The device is based on an FPGA-based Z80 processor with up to 28 MHz, DMA, copper , three AY8910 sound chips . It can display 256 colors from a palette of 512 with a resolution of 256 × 192 pixels (a free firmware update enabled an extended mode with 320 × 256 pixels), 16 colors from 512 in 512 × 192 hires mode, as well as extended spectrum and timex Graphic modes. Hardware scrolling and hardware sprites are also supported. 1024 K RAM can be expanded to 2048 K. An SD card is used as mass storage device. A Raspberry Pi Zero serves as an accelerator with which the Spectrum Next z. B. MP3 can play.
success
In Germany , the Sinclair ZX Spectrum was the second best-selling computer after the C64 until the Schneider / Amstrad CPC appeared . Its price in 1983 was around 400 DM for the 16KB model and 530 DM for 48KB. The ZX Spectrum achieved its greatest successes in Great Britain itself, where the computer appeared on the market considerably earlier than the Commodore 64. Also in the East and throughout the Eastern Bloc had the Spectrum some success, mainly because of the compatibility with the common there U880 - microprocessor and a variety of unlicensed replica models.
Over 5 million ZX Spectrum units were sold worldwide - there were a total of eight model variants. In Spain the ZX Spectrum was z. B. extremely popular for a long time; the model with 128 KB memory was even first launched in Spain. There have been many replicas of the ZX Spectrum. In particular, the basic model of the ZX Spectrum was relatively easy to replicate because it did not contain any special chips other than the ULA. Because of the large number of models, it is hardly possible to determine an approximately exact number of Spectrum-compatible computers built worldwide.
Emulators
For other computer systems there are a number of emulators that emulate the function of the ZX Spectrum. Advanced emulators can simulate multiple ZX-Spectrum models with high precision, including the sound chip, the exact speed of the original model, and undocumented instructions from the Z80 CPU. Some emulators (even for the C64 ) even allow the original cassette recordings to be loaded into the emulator via audio input or file.
literature
- Ian Stewart, Robin Jones: SINCLAIR ZX SPECTRUM. Programming made easy. Verlag Birkhäuser, Basel, 1983, ISBN 3-7643-1491-5
- Ian Stewart, Robin Jones: More tricks and programs with the ZX Spectrum. Verlag Birkhäuser, Basel, 1983, ISBN 3-7643-1532-6
- Ian Stewart, Robin Jones: ZX Spectrum machine code. Verlag Birkhäuser, Basel, 1983, ISBN 3-7643-1535-0
- Owen Bishop: Simple accessories for the ZX Spectrum, ZX81 and Jupiter Ace. Verlag Birkhäuser, Basel, 1984, ISBN 3-7643-1589-X
- E. Floegel: All about the spectrum. Verlag W. Hofacker, Holzk., 1983, ISBN 3-88963-108-8
- Roland G. Hülsmann: Much more than 33 programs for the SINCLAIR SPECTRUM. Verlag W. Hofacker, Holzk., 1983, ISBN 3-88963-144-4
- Steven Vickers, Robin Bradbeer: sinclair ZX SPECTRUM - INTRODUCTION. Sinclair Research, 1983, ISBN 3-88945-010-5
- Steven Vickers: sinclair ZX SPECTRUM - BASIC programming. Sinclair Research, 1983, ISBN 3-88945-011-3
- Bosetti: Zx Spectrum Tips & Tricks. Data Becker, 1985, ISBN 3-89011-075-4
- Sinclair ZX-Spectrum programs. CHIP special
- Jörg Reinmuth: Hardware expansion for ZX Spectrum. Brandenburgisches Verlagshaus, Berlin, 1990, ISBN 3-327-01030-7
- Christopher David Smith: The ZX Spectrum Ula: How to Design a Microcomputer (ZX Design Retro Computer). Zxdesign Technology and Media, 2010, ISBN 978-0-9565071-0-5
- Clive Sinclair, Paul Andrews and David Levy: Creating the Sinclair ZX Spectrum Vega. Retro Computers Ltd., 2015, ISBN 978-1-78538-290-1
Web links
- Biography of Sir Clive Sinclair and extensive collection of pictures of Sinclair computers (8bit-museum.de)
- 7000 ZX Spectrum Games ( Memento from May 14, 2013 in the Internet Archive ) (relaxate.com)
- Extensive information and pictures about the Sinclair ZX Spectrum (zock.com)
- worldofspectrum.org - Fan site for the Sinclair ZX Spectrum with lots of information
- Zx Spectrum Demos (3000), Games (5000) (zxaaa.net)
- Information on the peripheral devices available at the time (nvg.ntnu.no, English)
Individual evidence
- ↑ http://home.bt.com/news/world-news/april-23-1982-zx-spectrum-brings-affordable-and-colourful-computing-into-britains-homes-11363977137042
- ↑ How the Spectrum began a revolution. BBC , April 23, 2007, accessed March 9, 2014 .
- ↑ Szoftver: Programsugárzás. Gál Gábor, accessed February 12, 2019 (Hungarian).
- ↑ Software Catalog Spring 1986. Tasman Software (PDF; 5.3 MB)
- ↑ ZX Interface 2 Introduction. fruitcake.plus.com, accessed March 9, 2014 .
- ^ ZX Spectrum Next. Retrieved May 15, 2020 .
- ↑ About - ZX SPECTRUM NEXT. Retrieved May 15, 2020 (American English).
- ↑ c't magazin for computer technology, first edition 12/1983, page 85 (PDF) November 1983, accessed on January 22, 2016 .