Question: Were both Grundy NewBrain and Wave Mate Bullet around in the 1970's?

full_context: Document 1: Acorn Atom: The Acorn Atom is a home computer made by Acorn Computers Ltd from 1980 to 1982, when it was replaced by the BBC Micro (originally "Proton").
Document 2: Aster CT-80: The Aster CT-80, an early (1982) home/personal computer developed by the small Dutch company MCP (later renamed to Aster Computers), 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 big 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.
Document 3: ZX81: The ZX81 is a home computer produced by Sinclair Research and manufactured in Scotland by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and was designed to be a low-cost introduction to home computing for the general public. It was hugely successful, and more than 1.5 million units were sold before it was discontinued. The ZX81 found commercial success in many other countries, notably the United States, where it was initially sold as the ZX-81. Timex manufactured and distributed it under licence and enjoyed a substantial but brief boom in sales. Timex later produced its own versions of the ZX81 for the US market – the Timex Sinclair 1000 and Timex Sinclair 1500. Unauthorised clones of the ZX81 were produced in several countries.
Document 4: Timex Sinclair 1000: The Timex Sinclair 1000 (TS1000) was the first computer produced by Timex Sinclair, a joint venture between Timex Corporation and Sinclair Research. It was launched in July 1982, with a US sales price of US$99.95, making it the cheapest home computer to date; it was advertised as "the first computer under $100". The computer was aimed at regular home users. Unlike earlier computers aimed at home users, the TS1000 was not a kit which had to be soldered and assembled. As purchased, the TS1000 was fully assembled and ready to be plugged into the users' home TV (which served as a video monitor). The TS1000 was a slightly-modified version of the Sinclair ZX81 with an NTSC RF modulator, designed for use with North American TVs, instead of the UK PAL RF modulator which was used for units sold in Portugal. The TS1000 doubled the onboard RAM from 1 KB to 2 KB. The TS1000's casing had slightly more internal shielding but remained the same as Sinclair's, including the membrane keyboard. It had black-and-white graphics and no sound. It was followed by an improved version, the Timex Sinclair 1500 which had substantially more RAM (16 KB) and a lower price (US$80). However, the TS1500 did not achieve market success, given that the marketplace was by this time dominated by Commodore, RadioShack, Atari and Apple.
Document 5: TRS-80 MC-10: The TRS-80 MC-10 microcomputer is a lesser-known member of the TRS-80 line of home computers, produced by Tandy Corporation in the early 1980s and sold through their RadioShack chain of electronics stores. It was apparently designed as a low-cost alternative to Tandy's own TRS-80 Color Computer to compete with entry-level machines that had previously dominated the market, such as the Commodore VIC-20 and Sinclair ZX81.
Document 6: Acorn Computers: Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the UK, including the Acorn Electron and the Acorn Archimedes. Acorn's BBC Micro computer dominated the UK educational computer market during the 1980s. It is more known for its BBC Micro model B computer than for its other products.
Document 7: TRS-80: The TRS-80 Micro Computer System (TRS-80; later known as the Model I to distinguish it from successors) 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, Z-80 microprocessor". It was one of the earliest mass-produced and mass-marketed retail personal computers.
Document 8: Grundy NewBrain: The Grundy NewBrain was a microcomputer sold in the early 1980s by Grundy Business Systems Ltd of Teddington and Cambridge, England.
Document 9: Acorn Electron: The Acorn Electron is a budget version of the BBC Micro educational/home computer made by Acorn Computers Ltd. It has 32 kilobytes of RAM, and its ROM includes BBC BASIC v2 along with its operating system.
Document 10: Commodore 64x: The Commodore 64x is a replica PC based on the original Commodore 64, powered by standard x86 Intel processors ranging from the Intel Atom to the Intel Core i7. It was sold by Commodore USA starting in April 2011. Because Commodore USA went out of business after the death of its founder, Barry Altman, this machine is no longer available.
Document 11: Mark-8: The Mark-8 is a microcomputer design from 1974, based on the Intel 8008 CPU (which was the world's first 8-bit microprocessor). The Mark-8 was designed by graduate student Jonathan Titus and announced as a 'loose kit' in the July 1974 issue of "Radio-Electronics" magazine.
Document 12: TEC-1: The TEC-1 is a single-board kit computer first produced by the Australian hobbyist electronics magazine Talking Electronics in the early 1980s. It was based on the Zilog Z80 CPU, had 2K of RAM and 2K of ROM in a default configuration. Later versions used a 4k ROM with two different versions of the monitor software selectable via a switch. This allowed the early software presented in the magazine to be used with the later version of the TEC-1.
Document 13: Wave Mate Bullet: The Wave Mate Bullet was a Z80 single-board computer from the late 1970s and early 1980s which used the CP/M operating system. This computer is rarely seen now but has historical value as an early microcomputer pioneer. It was sold in Australia, the United States and Europe and was apparently popular in academic settings.
Document 14: BBC Micro: The BBC Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by the Acorn Computer company for the "BBC Computer Literacy Project", operated by the British Broadcasting Corporation. Designed with an emphasis on education, it was notable for its ruggedness, expandability, and the quality of its operating system. An accompanying 1982 television series ""The Computer Programme"" featuring Chris Serle learning to use the machine was also broadcast on BBC 2.
Document 15: Kenbak-1: The Kenbak-1 is considered by the Computer History Museum and the American Computer Museum to be the world's first "personal computer", invented by John V. Blankenbaker (1930-) of Kenbak Corporation in 1970, and first sold in early 1971. Only 50 machines were ever built. The system first sold for US$750. Today only 14 machines are believed to exist worldwide, in the hands of various collectors. Production of the Kenbak-1 stopped in 1973 as Kenbak failed, and was taken over by CTI Education Products, Inc. CTI rebranded the inventory and renamed it the H5050, though sales remained elusive.
ground_truth: no