A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor . The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PCB). Microcomputers became popular in the 1970s and 1980s with the advent of increasingly powerful microprocessors. The predecessors to these computers, mainframes and minicomputers , were comparatively much larger and more expensive (though indeed present-day mainframes such as the IBM System z machines use one or more custom microprocessors as their CPUs). Many microcomputers (when equipped with a keyboard and screen for input and output) are also personal computers (in the generic sense). An early use of the term "personal computer" in 1962 predates microprocessor-based designs. (See "Personal Computer: Computers at Companies" reference below) . A "microcomputer" used as an embedded control system may have no human-readable input and output devices. "Personal computer" may be used generically or may denote an IBM PC compatible machine.
139-531: The TRS-80 Micro Computer System ( TRS-80 , later renamed the Model I to distinguish it from successors) is a desktop microcomputer developed by American company Tandy Corporation and was sold through their Radio Shack stores. Launched in 1977, it is one of the earliest mass-produced and mass-marketed retail home computers . The name is an abbreviation of Tandy Radio Shack, Z80 [microprocessor] , referring to its Zilog Z80 8-bit microprocessor. The TRS-80 has
278-687: A Zilog Z80 processor clocked at 1.78 MHz (later models shipped with a Z80A). The initial Level I machines shipped in late 1977-early 1978 have only 4 KB of RAM. After the Expansion Interface and Level II BASIC were introduced in mid-1978, RAM configurations of 16 KB and up were offered (the first 16 KB was in the Model ;I itself and the remaining RAM in the Expansion Interface). The OS ROMs , I/O area, video memory, and OS work space occupy
417-804: A mail ordering catalog company migrating to opening retail locations in 1925, the first in Chicago . Through the 1980s, Sears was the largest retailer in the United States. In 2005, the company was bought by the management of the American big box discount chain Kmart , which upon completion of the merger, formed Sears Holdings . In 2018, it was the 31st-largest. After several years of declining sales, Sears's parent company filed for Chapter 11 bankruptcy on October 15, 2018. It announced on January 16, 2019, that it had won its bankruptcy auction, and that
556-578: A voice synthesizer , or a VOXBOX voice recognition unit. Originally, printing with the Model I required the Expansion Interface, but later Tandy made an alternative parallel printer interface available. The Model I Expansion Interface is the most troublesome part of the TRS-80 Model I system. It went through several revisions. The E/I connects to the CPU/keyboard with a 6-inch ribbon cable which
695-438: A "debounce" delay to the keyboard driver to avoid the noisy switch contacts. Tandy's KBFIX utility, the Model III, the last Model I firmware, and most third-party operating systems also implement the software fix, and Tandy changed the keyboard during the Model III's lifetime to an Alps Electric design with sealed switches. The Alps keyboard was available as an upgrade for the Model I for $ 79. The keyboard
834-412: A "special committee" to explore the sale of Kenmore. On September 24, 2018, the retailer's CEO warned that the company was "running out of time" to salvage its business. Sears Holdings filed for Chapter 11 bankruptcy on October 15, 2018, ahead of a $ 134 million debt payment due that day. On November 23, 2018, Sears Holdings released a list of 505 stores, including 266 Sears stores, that were for sale in
973-463: A better job, and Texas did not have a state income tax . Hired for his technical and retail experience, Leininger began working with French in June 1976. The company envisioned a kit, but Leininger persuaded the others that because "too many people can't solder", a preassembled computer would be better. Tandy had 11 million customers that might buy a microcomputer, but it would be much more expensive than
1112-452: A capacity of 180 kilobytes per single-sided floppy disk. The use of index-sync means that a " flippy disk " requires a second index hole and write-enable notch. One could purchase factory-made "flippies". Some software publishers formatted one side for Apple systems and the other for the TRS-80. The usual method of connecting floppy drives involves setting the drive letter via jumper blocks on
1251-727: A coming of age, financially, of the consumer sector. The company traded under the ticker symbol S and was a component of the Dow Jones Industrial Average from 1924 to 1999. In 1906, Sears opened its catalog plant and the Sears Merchandise Building Tower in Chicago's West Side . The building was the anchor of what would become the massive 40-acre (16 ha) Sears, Roebuck and Company Complex of offices, laboratories, and mail-order operations at Homan Avenue and Arthington Street. The complex served as corporate headquarters until 1973 when
1390-661: A company factory". Unlike competitor Commodore —which had announced the PET several months earlier but had not yet shipped any—Tandy had its own factories (capable of producing 18,000 computers a month) and distribution network, and even small towns had Radio Shack stores. The company announced plans to be selling by Christmas a range of peripherals and software for the TRS-80, began shipping computers by September, opened its first computer-only store in October, and delivered 5,000 computers to customers by December. Still forecasting 3,000 sales
1529-595: A computer based on a microprocessor – the Intel 8008 8-bit microprocessor. This Micral-N was marketed in early 1973 as a "Micro-ordinateur" or microcomputer , mainly for scientific and process-control applications. About a hundred Micral-N were installed in the next two years, followed by a new version based on the Intel 8080. Meanwhile, another French team developed the Alvan, a small computer for office automation which found clients in banks and other sectors. The first version
SECTION 10
#17327653170901668-463: A computer had to be big in size to be powerful, and thus decided to market them as calculators. Additionally, at that time, people were more likely to buy calculators than computers, and, purchasing agents also preferred the term "calculator" because purchasing a "computer" required additional layers of purchasing authority approvals. The Datapoint 2200 , made by CTC in 1970, was also comparable to microcomputers. While it contains no microprocessor,
1807-422: A disk operating system included in a series of programmable read-only memory chips (PROMs); 8 Kilobytes of RAM; IBM's Basic Assembly Language (BAL); a hard drive; a color display; a printer output; a 150 bit/s serial interface for connecting to a mainframe; and even the world's first microcomputer front panel. In early 1973, Sord Computer Corporation (now Toshiba Personal Computer System Corporation ) completed
1946-454: A double-density disk controller (based on the WD 1791 chip) were made by Percom (a Texas peripheral vendor), LNW, Tandy, and others. The Percom Doubler adds the ability to boot and use double density floppies using a Percom-modified TRSDOS called DoubleDOS. The LNDoubler adds the ability to read and write 5 + 1 ⁄ 4 -inch (130 mm) diskette drives with up to 720 KB of storage, and also
2085-401: A farm household could desire. Sales continued to proliferate, and the prosperity of the company and their vision for more significant expansion led Sears and Rosenwald to take the company public in 1906, with a stock placement of $ 40 million ($ 1.4 billion today). They had to incorporate a new company to bring the operation public; Sears and Rosenwald established Sears, Roebuck and Company with
2224-418: A full-stroke QWERTY keyboard, 4 KB dynamic random-access memory (DRAM) standard memory, small size and desk area, floating-point Level I BASIC language interpreter in read-only memory (ROM), 64-character-per-line video monitor , and a starting price of US$ 600 (equivalent to US$ 3,000 in 2023). A cassette tape drive for program storage was included in the original package. While the software environment
2363-496: A green-on-black display. Complaints about the video display quality were common. As Green wrote, "hells bells, [the monitor] is a cheap black and white television set with a bit of conversion for computer use". (The computer could be purchased without the Radio Shack monitor.) CPU access to the screen memory causes visible flicker . The bus arbitration logic blocks video display refresh (video-RAM reads) during CPU writes to
2502-538: A hardware problem that complicated loading programs from cassette recorders. Tandy offered a small board which was installed at a service center to correct the issue. The ROMs in later models were modified to correct this. Only the Model I uses an Expansion Interface; all later models have everything integrated in the same housing. The TRS-80 does not use the S-100 bus like other early 8080 and Z80-based computers. A proprietary Expansion Interface (E/I) box, which fits under
2641-492: A higher retail price to provide Tandy's typical profit margin. In February 1977 they showed their prototype, running a simple tax-accounting program, to Charles Tandy , head of Tandy Corporation. The program quickly crashed as the computer's implementation of Tiny BASIC could not handle the US$ 150,000 figure that Tandy typed in as his salary, and the two men added support for floating-point math to its Level I BASIC to prevent
2780-510: A loss of reliability on their tape recorders. With the Model III and improved electronics in the cassette interface, the standard speed increased to 1,500 baud which works reliably on most tape recorders. For loading and storing data from tape, the CPU creates the sound by switching the output voltage between three states, creating crude sine wave audio. The first version of the Model I also has
2919-419: A minicomputer or time-sharing service the opportunity to automate business functions, without (usually) hiring a full-time staff to operate the computers. A representative system of this era would have used an S100 bus , an 8-bit processor such as an Intel 8080 or Zilog Z80 , and either CP/M or MP/M operating system. The increasing availability and power of desktop computers for personal use attracted
SECTION 20
#17327653170903058-470: A new concept store called Sears Grand. Sears Grand stores carried everything that a regular Sears carries, and more. Sears Grand stores were about 175,000 to 225,000 square feet (16,300 to 20,900 m ). On November 17, 2004, Kmart Holdings Corporation announced it would acquire Sears, Roebuck, and Co. for $ 11 billion after Kmart completed its recovery from bankruptcy. As a part of the acquisition, Kmart Holding Corporation, along with Sears, Roebuck, and Co.,
3197-548: A new mail-order firm, again selling watches and jewelry, with Roebuck as his partner, operating as the A. C. Roebuck watch company. On September 16, 1893, they renamed the company Sears, Roebuck, and Co. and began to diversify the product lines offered in their catalogs. Before the Sears catalog, farmers near small rural towns usually purchased supplies, often at high prices and on credit, from local general stores with narrow selections of goods. Prices were negotiated and relied on
3336-455: A payroll for up to 15 people in a small business, teach children mathematics, store your favorite recipes or keep track of an investment portfolio. It can also play cards." Six sacks of mail arrived at Tandy headquarters asking about the computer, over 15,000 people called to purchase a TRS-80—paralyzing the company switchboard—and 250,000 joined the waiting list with a $ 100 deposit. Despite the internal skepticism, Radio Shack aggressively entered
3475-466: A publicity role. Sears offered Roebuck's half of the company to Chicago businessman Aaron Nusbaum , who in turn brought in his brother-in-law Julius Rosenwald , to whom Sears owed money. In August 1895, they bought Roebuck's half of the company for $ 75,000 ($ 2.7 million today), and that month the company was reincorporated in Illinois with a capital stock of $ 150,000 ($ 5.5 million today). The transaction
3614-469: A recurrence. The project was formally approved on 2 February 1977; Tandy revealed that he had already leaked the computer's existence to the press. When first inspecting the prototype, he remarked that even if it did not sell, the project could be worthy if only for the publicity it might generate. MITS sold 1,000 Altairs in February 1975 and was selling 10,000 a year. When Charles Tandy asked who would buy
3753-683: A reduced number of 425 stores would remain open, including 223 Sears stores. Sears was based in the Sears Tower in Chicago from 1973 until 1995, and was later headquartered in Hoffman Estates, Illinois from 1993 until 2021, the year when it announced that it would be selling its Hoffman Estates headquarters complex. On December 12, 2022, Sears Authorized Hometown Stores, LLC, and affiliated debtor Sears Hometown, Inc., filed for Chapter 11 bankruptcy protection, and on December 26 announced
3892-437: A software company, and the company had rejected his attempt for a Tandy Computer Center to sell non-Tandy computers. while the company's computer success helped Roach become Tandy's CEO. Selling computers did not change the company's "schlocky" image; the Radio Shack name embarrassed business customers, and Tandy executives disliked the "Trash-80" nickname for its products. By 1984, computers accounted for 35% of sales, however, and
4031-494: A standard feature of many commercial programs. They accept an "asterisk parameter", an asterisk (star) character typed following the program name when the program is run from the TRSDOS Ready prompt. When used following a spontaneous reboot (or an accidental reset, program crash, or exit to TRSDOS without saving data to disk), the program loads without initializing its data area(s), preserving any program data still present from
4170-499: A team of French engineers of the computer technology company R2E, led by its Head of Development, François Gernelle , created the first available microprocessor-based microcomputer, the Micral N. The same year the company filed their patents with the term "Micro-ordinateur", a literal equivalent of "Microcomputer", to designate a solid state machine designed with a microprocessor. In the US
4309-557: A time, although they can often be modified with software or hardware to concurrently serve more than one user. Microcomputers fit well on or under desks or tables, so that they are within easy access of users. Bigger computers like minicomputers , mainframes , and supercomputers take up large cabinets or even dedicated rooms. A microcomputer comes equipped with at least one type of data storage, usually RAM . Although some microcomputers (particularly early 8-bit home micros) perform tasks using RAM alone, some form of secondary storage
TRS-80 - Misplaced Pages Continue
4448-661: A year, Radio Shack sold over 10,000 TRS-80s in its first one and a half months of sales, 55,000 in its first year, and over 200,000 during the product's lifetime; one entered the Smithsonian 's National Museum of American History . By mid-1978 the waits of two months or more for delivery were over, and the company could state in advertisements that TRS-80 was "on demonstration and available from stock now at every Radio Shack store in this community!" The first units, ordered unseen, were delivered in November 1977, and rolled out to
4587-399: Is memory-mapped so that certain locations in the processor's memory space correspond to the status of a group of keys. The color of the 12 in (300 mm) KCS 172 RCA monitor's text is faintly blue (the standard P4 phosphor used in black-and-white televisions). Green and amber filters, or replacement tubes to reduce eye fatigue were popular aftermarket items. Later models came with
4726-410: Is 64. This can be worked around by deleting the unused bit and piggybacking an eighth 2102 chip onto another. The alphanumeric symbols are displayed in 5×7 matrices of pixels . The 1978 manual for the popular word processor Electric Pencil came with instructions for modifying the computer. Although the modification needs to be disabled for Level II BASIC, its design became the industry standard and
4865-409: Is a continuous loop tape drive, dubbed the stringy floppy or ESF. It requires no Expansion Interface, plugging directly into the TRS-80's 40-pin expansion bus, is much less expensive than a floppy drive, can read and write random-access data like a floppy drive unlike a cassette tape, and it transfers data at up to 14,400 baud . Exatron tape cartridges store over 64 KB of data. The ESF can coexist with
5004-474: Is ignored, and the eighth toggles graphics mode. The reason that the seventh bit is ignored is due to the company's decision to have only seven 2102 static-RAM chips installed on the computer's motherboard instead of eight to keep the manufacturing cost low. Thus, there are no lowercase letters in the TRS-80 character set of an unmodified Model I, and the number of both graphics symbols and alphanumeric symbols
5143-783: Is jumpered to their number on the chain, or even an IBM PC "twist" cable, which requires setting each drive number to 1, but only permits two drives on the chain. Although third-party DOSes allow the user to define virtually any floppy format wanted, the "lowest common denominator" format for TRS-80s is the baseline single-density, single-sided, 35-40 track format of the Model I. Third-party vendors like Aerocomp made available double-sided and 80 track 5 + 1 ⁄ 4 -inch and later 3 + 1 ⁄ 2 -inch floppy drives with up to 720 KB of storage each. These new drives are half-height and therefore require different or modified drive housings. An alternative to cassette tape and floppy disk storage from Exatron sold over 4,000 units by 1981. The device
5282-806: Is normally desirable. In the early days of home micros, this was often a data cassette deck (in many cases as an external unit). Later, secondary storage (particularly in the form of floppy disk and hard disk drives) were built into the microcomputer case. Although they did not contain any microprocessors, but were built around transistor-transistor logic (TTL), Hewlett-Packard calculators as far back as 1968 had various levels of programmability comparable to microcomputers. The HP 9100B (1968) had rudimentary conditional (if) statements, statement line numbers, jump statements ( go to ), registers that could be used as variables, and primitive subroutines. The programming language resembled assembly language in many ways. Later models incrementally added more features, including
5421-508: Is present in Drive 0, it hangs there until the user either presses RESET on the back of the computer, which causes it to attempt to boot the disk again, or Break + Reset was pressed, which drops the computer into BASIC. Due to the above-mentioned problems with potentially corrupting disks, it is recommended to power up to the garbage screen with the disk drives empty, insert a system disk, and then hit RESET . InfoWorld compared
5560-534: Is sometimes called the first generation of microcomputers. Many companies such as DEC , National Semiconductor , Texas Instruments offered their microcomputers for use in terminal control, peripheral device interface control and industrial machine control. There were also machines for engineering development and hobbyist personal use. In 1975, the Processor Technology SOL-20 was designed, which consisted of one board which included all
5699-479: Is unreliable, partly because the interface lacked an external data separator (buffer). The early versions of TRSDOS were also buggy, and not helped by the Western Digital FD1771 chip which cannot reliably report its status for several instruction cycles after it receives a command. A common method of handling the delay was to issue a command to the 1771, perform several "NOP" instructions, then query
TRS-80 - Misplaced Pages Continue
5838-405: Is unshielded against RF interference and its card edge connector tends to oxidize due to its base metal contacts. This demands periodic cleaning with a pencil eraser in order to avoid spontaneous reboots, which contributes to its "Trash-80" sobriquet. Aftermarket connectors plated with gold solved this problem permanently. Software developers also responded by devising a recovery method which became
5977-475: Is used to depress the power button and the E/I has no power LED, making it difficult to determine if it is running or not. The expansion unit requires a second power supply, identical to the base unit power supply. An interior recess holds both supplies. The user is instructed to power on and power off all peripherals in proper order to avoid corrupting data or potentially damaging hardware components. The manuals for
6116-450: The BASIC programming language (HP 9830A in 1971). Some models had tape storage and small printers. However, displays were limited to one line at a time. The HP 9100A was referred to as a personal computer in an advertisement in a 1968 Science magazine, but that advertisement was quickly dropped. HP was reluctant to sell them as "computers" because the perception at that time was that
6255-600: The Commonwealth of Puerto Rico . In 1997, Sears sold 85% of its Mexico affiliate to Grupo Carso . Sears Holdings continued to produce specialty catalogs and reintroduced a smaller version of the Holiday Wish Book in 2007. In 2003, Sears sold its U.S. retail credit card operation to Citibank . The remaining card operations for Sears Canada were sold to JPMorgan Chase in August 2005. In 2003, Sears opened
6394-919: The Discover credit card in 1985. However, these actions have been said to have distracted management's attention from the core retail business and allowed competing retailers to gain significant ground, culminating with Walmart surpassing Sears as the largest retailer in the United States in 1990. In the 1990s, the company began divesting itself of many non-retail entities, which were detrimental to its bottom line. Sears spun off its financial services arm, which included brokerage business Dean Witter Reynolds and Discover Card. It sold its mall building subsidiary Homart to General Growth Properties in 1995. Sears later acquired hardware chain Orchard Supply Hardware in 1996 and started home improvement store The Great Indoors in 1997. The cost of distributing
6533-689: The Sears Archer 600 typewriter as a rebranded Silverette model, manufactured by Silver Seiko Ltd. of Japan. The success of Sears outdoor products raised the attention of the Federal Government and the antitrust laws. Sears purchased David Bradley to manufacture farm and lawn equipment. Its success was broken up in 1962 as they sold more plows than John Deere. Sears sold half of the David Bradley factory in Bradley, Illinois to
6672-436: The Sears Tower was completed and served as the base of the mail-order catalog business until 1995. By 1907, under Rosenwald's leadership as vice president and treasurer, annual sales of the company climbed to roughly $ 50 million ($ 1.6 billion today). Sears resigned from the presidency in 1908 due to declining health, with Rosenwald named president and chairman of the board and taking on full control. In 1910, Sears acquired
6811-538: The US$ 30 median price of a Radio Shack product, and a great risk for the very conservative company. Executives feared losing money as Sears did with Cartrivision , and many opposed the project; one executive told French, "Don't waste my time—we can't sell computers." As the popularity of CB radio —at one point comprising more than 20% of Radio Shack's sales—declined, however, the company sought new products. In December 1976 French and Leininger received official approval for
6950-492: The Western Digital 1771 single-density floppy disk controller chip. The industry standard Shugart Associates SA-400 minifloppy disk drive was used. Four floppy drives can be daisy-chained to the Model I. The last drive in the chain is supposed to have a termination resistor installed but often it is not needed as it is integrated into later cables. Demand for Model I drives greatly exceeded supply at first. The drive
7089-614: The cable spaghetti connecting the TRS-80 Model I's various components to the snakes in Raiders of the Lost Ark . Radio Shack offered a "TRS-80 System Desk" that concealed nearly all the cabling. It can accommodate the complete computer system plus up to four floppy drives and the Quick Printer. Since the cable connecting the Expansion Interface carries the system bus, it is short (about 6 inches). The user has no choice but to place
SECTION 50
#17327653170907228-566: The instruction set of its custom TTL processor was the basis of the instruction set for the Intel 8008 , and for practical purposes the system behaves approximately as if it contains an 8008. This is because Intel was the contractor in charge of developing the Datapoint's CPU, but ultimately CTC rejected the 8008 design because it needed 20 support chips. Another early system, the Kenbak-1 ,
7367-512: The 1771 for the result. Early TRSDOS neglects the required yet undocumented wait period, and thus false status often returns to the OS, generating random errors and crashes. Once the 1771 delay was implemented, it was fairly reliable. In 1981, Steve Ciarcia published in Byte the design for a homemade, improved expansion interface with more RAM and a disk controller for the TRS-80. A data separator and
7506-533: The 1920s to the 1950s, Sears built many urban department stores in the U.S., Canada, and Mexico (apart from, but not far from, existing central business districts ), and they overshadowed the mail-order business. Following World War II, the company expanded into suburban markets and malls. In 1959, it had formed the Homart Development Company for developing malls. Many of the company's stores have undergone major renovations or replacements since
7645-460: The 1980s. Sears began to diversify in the 1930s, creating Allstate Insurance Company in 1931 and placing Allstate representatives in its stores in 1934 (Allstate was also used as a house brand on a range of motorized vehicles sold by Sears). Over the decades, it established major national brands, such as Kenmore , Craftsman , DieHard , Silvertone , Supertone , and Toughskins — and marketed widely under its private labels , e.g., marketing
7784-549: The Altair itself was only a mild commercial success, it helped spark a huge industry. By 1977, the introduction of the second microcomputer generation as consumer goods , known as home computers , made them considerably easier to use than their predecessors because their predecessors' operation often demanded thorough familiarity with practical electronics. The ability to connect to a monitor (screen) or TV set allowed visual manipulation of text and numbers. The BASIC language, which
7923-600: The CTR-41 unit with the CTR-80 which had built-in AGC circuitry (and no volume control). This helped the situation, but tape operation is still unreliable. TRS-80 Model I computers with Level I BASIC read and write tapes at 250 baud (about 30 bytes per second); Level II BASIC doubles this to 500 baud (about 60 bytes per second). Some programmers wrote machine-language programs that increase the speed to up to 2,000 bits per second without
8062-764: The David Bradley Plow company. This acquisition would lead to the manufacturing of riding mowers, chainsaws, tillers, etc., in the Bradley Illinois factory. The company was badly hurt during 1919–21 as a severe depression hit the nation's farms after farmers had over-expanded their holdings. To bail out the company, Rosenwald pledged $ 21 million ($ 358.7 million today) of his personal wealth in 1921. By 1922, Sears regained financial stability. Rosenwald decided to shift emphasis to urban America and brought in Robert E. Wood to take charge. Rosenwald oversaw
8201-464: The E/I directly behind the computer with the monitor on top. This causes problems for a non-Tandy monitor whose case did not fit the mounting holes. Also, the friction fit of the edge connector on the already short interconnect cable makes it possible to disconnect the system bus from the CPU if either unit is bumped during operation. Radio Shack introduced floppy drives in July 1978, about six months after
8340-623: The IBM PC itself was widely imitated, as well as the term. The component parts were commonly available to producers and the BIOS was reverse engineered through cleanroom design techniques. IBM PC compatible "clones" became commonplace, and the terms "personal computer", and especially "PC", stuck with the general public, often specifically for a computer compatible with DOS (or nowadays Windows). Monitors, keyboards and other devices for input and output may be integrated or separate. Computer memory in
8479-430: The Model I went on sale. The Model I disk operating system TRSDOS was written by Randy Cook under license from Radio Shack; Randy claimed to have been paid $ 3000 for it. The first version released to the public was a buggy v2.0. This was quickly replaced by v2.1. Floppy disk operation requires buying the Expansion Interface, which included a single-density floppy disk interface (with a formatted capacity of 85K) based on
SECTION 60
#17327653170908618-442: The Model III launch in mid-1980, Tandy stated that the Model I was still sold, but it was discontinued by the end of the year. Tandy cited one of the main reasons as being the prohibitive cost of redesigning it to meet stricter FCC regulations covering the significant levels of radio-frequency interference emitted by the original design. The Model I radiated so much interference that, while playing games, an AM radio placed next to
8757-479: The Model III was succeeded by the compatible TRS-80 Model 4 . Following the original Model I and its compatible descendants , the TRS-80 name became a generic brand used on other unrelated computer lines sold by Tandy, including the TRS-80 Model II , TRS-80 Model 2000 , TRS-80 Model 100 , TRS-80 Color Computer , and TRS-80 Pocket Computer . In the mid-1970s, Tandy Corporation 's Radio Shack division
8896-659: The Newark Ohio Company that was shortly acquired by Roper Industries. Sears reached its pinnacle in the 1970s. In 1974, Sears completed the 110-story Sears Tower in Chicago, which became the world's tallest building , a title it took from the former Twin Towers in New York. Upon moving out of Chicago, Sears sold the Sears Tower in 1988. In the sale contract of the tower, Sears retained its naming rights to
9035-677: The Prairie Stone campus. The Sears catalog became known in the industry as "the Consumers' Bible". The company began selling to foreign customers after the American occupation of Greenland in World War II and the Philippines, among others, when locals ordered from catalogs left by soldiers. Novelists and story writers often portrayed the importance of the catalog in the emotional lives of rural folk. The catalog also entered
9174-440: The R.W. Sears Watch Company. That year, he met Alvah Curtis Roebuck , a watch repairman. In 1887, Sears and Roebuck relocated the business to Chicago, and the company published Richard Sears's first mail-order catalog, offering watches, diamonds, and jewelry. In 1889, Sears sold his business for $ 100,000 ($ 3 million in 2021 dollars) and relocated to Iowa, planning to be a rural banker. He returned to Chicago in 1892 and established
9313-702: The SMP80/08, which used the Intel 8008 microprocessor. The SMP80/08, however, did not have a commercial release. After the first general-purpose microprocessor, the Intel 8080 , was announced in April 1974, Sord announced the SMP80/x, the first microcomputer to use the 8080, in May 1974. Virtually all early microcomputers were essentially boxes with lights and switches; one had to read and understand binary numbers and machine language to program and use them (the Datapoint 2200
9452-584: The Sears Essentials format, only to change them later to Sears Grands. The combined company's profits peaked at $ 1.5 billion in 2006. By 2010, the company was no longer profitable; from 2011 to 2016, the company lost $ 10.4 billion. In 2014, its total debt ($ 4.2 billion at the end of January 2017) exceeded its market capitalization ($ 974.1 million as of March 21, 2017). Sears declined from more than 3,500 physical stores to 695 U.S. stores from 2010 to 2017. Sales at Sears stores dropped 10.3 percent in
9591-406: The TRS-80 advise turning on the monitor first, then any peripherals attached to the E/I (if multiple disk drives are attached, the last drive on the chain is to be powered on first and work down from there), the E/I, and the computer last. When powering down, the computer is to be turned off first, followed by the monitor, E/I, and peripherals. In addition, users are instructed to remove all disks from
9730-472: The TRS-80 data cassette drive. Exatron also made a complementary RAM expansion board that installed in the TRS-80 keyboard to increase memory to 48 KB without the EI. Microcomputer The abbreviation "micro" was common during the 1970s and 1980s, but has since fallen out of common usage. The term microcomputer came into popular use after the introduction of the minicomputer , although Isaac Asimov used
9869-543: The TRS-80 had the largest selection of software in the microcomputer market. Until 1982, the TRS-80 was the bestselling PC line, outselling the Apple II by a factor of five according to one analysis. The broadly compatible TRS-80 Model III was released in the middle of 1980. The Model I was discontinued shortly thereafter, primarily due to stricter Federal Communications Commission (FCC) regulations on radio-frequency interference to nearby electronic devices. In April 1983,
10008-623: The VRAM, causing a short black line. This has little effect on normal BASIC programs, but fast programs made with assembly language can be affected. Software authors worked to minimize the effect, and many arcade-style games are available for the Tandy TRS-80. Because of bandwidth problems in the interface card that replaced the TV's tuner, the display loses horizontal sync if large areas of white are displayed. A simple half-hour hardware fix corrects
10147-439: The attention of more software developers. As the industry matured, the market for personal computers standardized around IBM PC compatibles running DOS , and later Windows . Modern desktop computers, video game consoles , laptops , tablet PCs , and many types of handheld devices , including mobile phones , pocket calculators , and industrial embedded systems , may all be considered examples of microcomputers according to
10286-519: The bankruptcy process, while all others would hold liquidation sales. On January 16, 2019, Sears Holdings announced it would remain open after Lampert won a bankruptcy auction for the company with an offer to keep about 400 stores open. On February 7, 2019, a bankruptcy judge approved a $ 5.2 billion plan by Sears's chairman and biggest shareholder to keep the business going. The approval meant roughly 425 stores, including 223 Sears stores, and 45,000 jobs would be preserved. In April 2019, Sears announced
10425-906: The basic system (CPU/keyboard and video monitor) was US$ 500 and a US$ 50 deposit was required, with a money-back guarantee at time of delivery. By 1978, Tandy/Radio Shack promoted itself as "The Biggest Name in Little Computers". By 1979 1,600 employees built computers in six factories. Kilobaud Microcomputing estimated in 1980 that Tandy was selling three times as many computers as Apple Computer , with both companies ahead of Commodore. By 1981, InfoWorld described Radio Shack as "the dominant supplier of small computers". Hundreds of small companies produced TRS-80 software and accessories, and Adam Osborne described Tandy as "the number-one microcomputer manufacturer" despite having "so few roots in microcomputing". That year Leininger left his job as director for advanced research; French had left to found
10564-456: The black-and-silver colors of the RCA CRT unit's cabinet for the TRS-80 units as well. Having spent less than US$ 150,000 on development, Radio Shack announced the TRS-80 (Tandy Radio Shack) at a New York City press conference on August 3, 1977. It cost US$ 399 (equivalent to $ 2,000 in 2023), or US$ 599 (equivalent to $ 3,000 in 2023) with a 12" monitor and a Radio Shack tape recorder;
10703-400: The brand's huge popularity helped attract customers. Sears retail stores were pioneering and broke the conventions of the time in three ways: Many stores at this time were designed by architect George C. Nimmons and his firms. The architecture was driven by merchandising needs rather than the desired outer appearance. This made the stores excellent examples of the modern architecture of
10842-483: The building until 2003, but the Sears Tower retained the name until early 2009, when London-based insurer Willis Group Holdings, Ltd. was given the building's naming rights to encourage them to occupy the building. Sears moved to the new Prairie Stone Business Park in Hoffman Estates, Illinois, between 1993 and 1995. The Sears Centre is a 10,001-seat multi-purpose arena located in Hoffman Estates adjacent to
10981-416: The business" and "never our large market". Although the press conference did not receive much media attention because of a terrorist bombing elsewhere in the city , the computer received much more publicity at Boston University 's Personal Computer Fair two days later. A front-page Associated Press article discussed the novelty of a large consumer-electronics company selling a home computer that could "do
11120-475: The cassette port and plugging an amplifier into the cassette "Mic" line. Most games use this ability for sound effects. An adapter was available to use Atari joysticks . User data was originally stored on cassette tape . Radio Shack's model CTR-41 cassette recorder was included with the US$ 599 package. The software-based cassette tape interface is slow and erratic; Green described it as "crummy ... drives users up
11259-666: The company announced that Transform Holdco would acquire Sears Hometown & Outlet Stores . As per deal, it might need to divest its Sears Outlet division to gain approval. On August 6, 2019, it was announced that 26 stores would close that October, including 21 Sears stores, among them the last Sears stores in Alabama and West Virginia , at Riverchase Galleria in Hoover and at Huntington Mall in Barboursville , respectively. The announcement also included plans to "accelerate
11398-571: The company had 500 Tandy Radio Shack Computer Centers. By 1979, when Radio Shack launched the business-oriented, and incompatible, TRS-80 Model II , the TRS-80 was officially renamed the TRS-80 Model I to distinguish the two product lines. After some exhibitors at the 1979 Northeast Computer Show were forced to clarify that their products bearing the TRS-80 name were not affiliated with Radio Shack, publications and advertisers briefly began to use "S-80" generically rather than "TRS-80" under scare of legal action, though this never materialized. Following
11537-417: The company was looking to focus on becoming a more tech-driven retailer. Sears's CEO and top shareholder said the sell-off of key assets in the last year had given the retailer the money it needs to speed up its transformation. Sears Holdings had lost a total of US$ 7 billion in the four years to 2015. In part, the retailer was trying to curb losses by using a loyalty program called Shop Your Way. Sears believed
11676-416: The computer can be used to provide sounds. Radio Shack offered upgrades (double-density floppy controller, LDOS, memory, reliable keyboard with numeric keypad, lowercase, Level II, RS-232C) as late as its 1984 catalog. The Model I combines the mainboard and keyboard into one unit, which became a design trend in the 8-bit microcomputer era, although the Model I has a separate power supply unit. It uses
11815-574: The computer, company president Lewis Kornfeld admitted that they did not know if anyone would, but suggested that small businesses and schools might. Knowing that demand was very strong for the US$ 795 Altair—which cost more than $ 1,000 with a monitor—Leininger suggested that Radio Shack could sell 50,000 computers, but no one else believed him; Roach called the figure "horseshit", as the company had never sold that many of anything at that price. Roach and Kornfeld suggested 1,000 to 3,000 per year; 3,000
11954-507: The current Ford line ]). By 1895, the company was producing a 532-page catalog. Sales were over $ 400,000 ($ 12 million in 2021 dollars) in 1893 and over $ 750,000 ($ 20 million in 2021 dollars) two years later. By 1896, dolls, stoves, and groceries were added to the catalog. Despite the strong and growing sales, the national Panic of 1893 led to a full-scale economic depression , causing a cash squeeze and large quantities of unsold merchandise by 1895. Roebuck decided to quit, returning later in
12093-401: The data. Then it is halted to rewind the tape and restart the load. Users were instructed to save multiple copies of a software program file, especially if audio tape cassettes instead of certified data tape was used. Automatic gain control or indicator circuits can be constructed to improve the loading process (the owner's manual provides complete circuit diagrams for the whole machine, including
12232-465: The definition given above. By the early 2000s, everyday use of the expression "microcomputer" (and in particular "micro") declined significantly from its peak in the mid-1980s. The term is most commonly associated with the most popular 8-bit home computers (such as the Apple II , ZX Spectrum , Commodore 64 , BBC Micro , and TRS-80 ) and small-business CP/M -based microcomputers. In colloquial usage, "microcomputer" has been largely supplanted by
12371-520: The design and construction of the firm's first department store, built on land within the Sears, Roebuck, and Company Complex. The store opened in 1925. In 1924, Rosenwald resigned the presidency but remained as chair until he died in 1932; his goal was to devote more time to philanthropy. The first store opened on February 2, 1925, as an experiment in the North Lawndale Sears, Roebuck and Company Complex . Despite its remote location on
12510-469: The drive controller board, but Tandy opted for a slightly more user-friendly technique where all four select pins on the drives are jumpered and the ribbon cable is missing the Drive Select line. Thus, the user does not need to worry about moving jumpers around depending on which position on the chain a drive was in. A standard flat floppy ribbon cable is usable on the Model I, in which case the drives
12649-407: The drives during power up or down (or else leave the drive door open to disengage the read/write head from the disk). This is because a transient electrical surge from the drive's read/write head would create a magnetic pulse that could corrupt data. This was a common problem on many early floppy drives. The E/I displays a screen full of garbage characters on power up and unless a bootable system disk
12788-570: The earliest models such as the Altair 8800 were often sold as kits to be assembled by the user, and came with as little as 256 bytes of RAM , and no input/output devices other than indicator lights and switches, useful as a proof of concept to demonstrate what such a simple device could do. As microprocessors and semiconductor memory became less expensive, microcomputers grew cheaper and easier to use. All these improvements in cost and usability resulted in an explosion in their popularity during
12927-677: The expansion of our smaller store formats which includes opening additional Home & Life stores and adding several hundred Sears Hometown stores after the Sears Hometown and Outlet transaction closes." On August 31, 2019, management announced that Transform would close an additional 92 stores, including 15 Sears stores, by the end of 2019. Near the end of 2019, Sears sold the brand name DieHard to Advance Auto Parts for $ 200 million. A total of 100 more stores closed by January 2020. 51 Sears stores were closed in February 2020. More stores continued to close throughout 2020 and 2021, including
13066-588: The family fortune in a speculative stock deal. Sears moved across the state to work as a railroad station agent in North Redwood , then Minneapolis . While he was in North Redwood, a jeweler refused delivery on a shipment of watches. Sears purchased them and sold them at a low price to the station agents, making a profit. He started a mail-order watch business in Minneapolis in 1886, calling it
13205-690: The final Sears in Maine at The Maine Mall. In September 2021, the company's website listed 35 Sears stores. That month, Sears announced that it would close more stores, including the last Sears store in New York City. The New York City Sears closed by November 24, 2021, with the potential to be redeveloped. Transformco announced in December 2021 its plans to sell the 2.3 million-square-foot Sears headquarters in Hoffman Estates, which includes 100 acres of undeveloped land. On January 19, 2022, Sears shut
13344-530: The final quarter of 2016 when compared to the same period in 2015. Sears spent much of 2014 and 2015 selling off portions of its balance sheet; namely, Lands' End and its stake in Sears Canada , one of the biggest e-commerce players in Canada, with Can$ 505 million in sales in 2015—more than Walmart and others who had begun pushing aggressively into online sales, such as Canadian Tire . Sears stated that
13483-558: The first 16 KB of memory space on the Model I. The remaining 48 KB of the 64 KB memory map space is available for program use, subject to the amount of physical RAM installed. Although the Z80 CPU can use port-based I/O, the Model I's I/O is memory-mapped aside from the cassette tape and RS-232 serial ports. The TRS-80 Model I keyboard uses mechanical switches that suffer from " keyboard bounce ", resulting in multiple letters being typed per keystroke. The problem
13622-1050: The first of its Christmas catalogs known as the " Sears Wishbook ", a catalog featuring toys and gifts, separate from the annual Christmas Catalog. From 1908 to 1940, it included ready-to-assemble Sears Catalog Home kit houses. Sears opened a small store in Downtown Havana , Cuba in 1942. Sears opened its first store in Mexico City in 1947; the Mexican stores would later spin off into Sears Mexico , now owned by billionaire Carlos Slim 's Grupo Sanborns , which in 2020 operated more than 75 stores across Mexico. Sears had sales of US$ 78 million in other territories in 1953. Over time, Sears expanded into all Central American countries, Cuba, Puerto Rico, Colombia, Venezuela, Ecuador, Peru, Brazil, and Spain. Currently Sears operates in Mexico, Guatemala, El Salvador, and Puerto Rico. From
13761-452: The form of RAM , and at least one other less volatile, memory storage device are usually combined with the CPU on a system bus in one unit. Other devices that make up a complete microcomputer system include batteries, a power supply unit, a keyboard and various input/output devices used to convey information to and from a human operator ( printers , monitors , human interface devices ). Microcomputers are designed to serve only one user at
13900-439: The language, particularly of rural dwellers, as a euphemism for toilet paper, as its pages could be torn out and used as such. In addition, for many rural African-Americans, especially in areas dominated by Jim Crow racial segregation , the Sears catalog was a vital retail alternative to local white-population-dominated stores, bypassing the stores' frequent intention to deny them fair access to their merchandise. However, as
14039-581: The late 1970s and early 1980s. A large number of computer makers packaged microcomputers for use in small business applications. By 1979, many companies such as Cromemco , Processor Technology , IMSAI , North Star Computers , Southwest Technical Products Corporation , Ohio Scientific , Altos Computer Systems , Morrow Designs and others produced systems designed for resourceful end users or consulting firms to deliver business systems such as accounting, database management and word processing to small businesses. This allowed businesses unable to afford leasing of
14178-419: The legal name Sears, Roebuck and Co. , in the state of New York, which effectively replaced the original company. The current company inherits the history of the old company, celebrating the original 1892 incorporation, rather than the 1906 revision, as the start of the company. Sears's successful 1906 initial public offering (IPO) marks the first major retail IPO in American financial history and represented
14317-462: The liquidation of the 115 largely owner-operated Hometown stores. As of November 2024, there are nine Sears stores remaining, with eight in the mainland U.S. and one location in the U.S. territory of Puerto Rico. Richard Warren Sears was born in 1863 in Stewartville, Minnesota , to a wealthy family which moved to nearby Spring Valley . In 1879, his father died shortly after losing
14456-425: The market. The company advertised " The $ 599 personal computer " as "the most important, useful, exciting, electronic product of our time". Kornfeld stated when announcing the TRS-80, "This device is inevitably in the future of everyone in the civilized world—in some way—now and so far as ahead as one can think", and Tandy's 1977 annual report called the computer "probably the most important product we've ever built in
14595-572: The membership scheme would enhance repeat business and customer loyalty in the long term. CEO Eddie Lampert also concluded an arrangement that sold the Craftsman brand to Stanley Black & Decker Inc. for approximately US$ 900 million. In October 2017, Sears and appliance manufacturer Whirlpool Corporation ended their 101-year-old association, reportedly due to pricing issues, although Whirlpool continued supplying Sears with Kenmore -branded appliances. In May 2018, Sears announced it had formed
14734-404: The most expensive product Radio Shack previously sold was a US$ 500 stereo. The company hoped that the new computer would help Radio Shack sell higher-priced products, and improve its "schlocky" image among customers. Small businesses were the primary target market, followed by educators, then consumers and hobbyists; despite its hobbyist customer base, Radio Shack saw them as "not the mainstream of
14873-404: The nation urbanized, Sears's catalog business faced competition from city department stores. Rural America's population was slow-growing and possessed far less spending power than urban America. In the 1980s, the company began to diversify into non-retail entities such as buying Dean Witter and Coldwell Banker in 1981. In 1984, it launched Prodigy as a joint venture with IBM , and introduced
15012-519: The older 8-inch (200 mm) diskettes with up to 1,155 KB. Near the end of the Model I's lifespan in 1982, upgrades were offered to replace its original controller with a double-density one. The first disk drives offered on the Model I were Shugart SA-400s which supported 35 tracks and was the sole 5 + 1 ⁄ 4 -inch drive on the market in 1977–78. By 1979, other manufacturers began offering drives. Models 3/4/4P uses Tandon TM-100 40-track drives. The combination of 40 tracks and double density gives
15151-515: The once highly influential general merchandise catalog became prohibitive; sales and profits had declined. The company discontinued the catalog in 1993. It dismissed 50,000 workers who had filled the orders. In 1992, the company posted a $ 3.9 billion loss, the largest ever from an American retailer. In 1992, California successfully sued the company for falsely finding things wrong with automobiles in for repair for other reasons. In 1997, criminal charges were made. In 1998, Sears announced it had sold
15290-519: The opening of three new stores with a limited set of merchandise under the name Sears Home & Life. Also that month, Sears closed its store at Windward Mall in Kaneohe, Hawaii , and its store at Oakbrook Center in Oak Brook, Illinois (which was razed and already rebuilt as a 1-story store), making it the first post-bankruptcy closure for the brand since being bought by ESL. On June 3, 2019,
15429-513: The outskirts of Chicago, its success led to dozens of further openings across the country, many in conjunction with the company's mail-order offices, typically in lower-middle-class and working-class neighborhoods, far from the main downtown shopping district. This was considered highly unconventional at a time when shopping was concentrated in city centers, but through World War II , there was an extensive streetcar network in Chicago and other U.S. cities. However, rapidly increasing car ownership and
15568-468: The parts of the computer system. The SOL-20 had built-in EPROM software which eliminated the need for rows of switches and lights. The MITS Altair just mentioned played an instrumental role in sparking significant hobbyist interest, which itself eventually led to the founding and success of many well-known personal computer hardware and software companies, such as Microsoft and Apple Computer . Although
15707-495: The peripheral interfaces, with notes on operation). An alternative to using tape was data transmissions from the BBC 's Chip Shop programme in the UK, which broadcast software for several different microcomputers over the radio. A special program was loaded using the conventional tape interface. Then the radio broadcast was connected to the cassette tape interface. Tandy eventually replaced
15846-427: The pre-reboot session. Thus, for example, if a VisiCalc user suffers a spontaneous reboot, to recover data the user enters V + C + SPACE + ✶ at TRSDOS Ready, and Visicalc restores the previous computing session intact. The power button on the E/I is difficult to operate as it is recessed so as to guard against the user accidentally hitting it and turning it off while in use. A pencil eraser or similar object
15985-401: The problem. The graphics are displayed at a resolution of 64×16 character positions on a screen measuring 7.5 inches (19 cm) wide and 6.625 inches (16.83 cm) tall. Each character is composed of a 2×3 matrix of pixels, and corresponds to one byte of the 1 KB video memory used by the TRS-80. In each of those bytes, the first six bits control which pixel is displayed. The seventh bit
16124-439: The project but were told to emphasize cost savings; for example, leaving out lowercase characters saved US$ 1.50 in components and reduced the retail price by US$ 5 . The original US$ 199 retail price required manufacturing cost of US$ 80 ; the first design had a membrane keyboard and no video monitor. Leininger persuaded Roach and French to include a better keyboard, a monitor, datacassette storage, and other features requiring
16263-625: The remaining 15 Sears Auto Centers in the United States with a message on the Sears Auto Center website stating: "Auto Centers have closed for business. We appreciate your patronage over the years. If you have any questions concerning warranty claims, please visit us at Sears Help." In May 2022, it was announced that roughly 100 more Sears Hometown stores, including the last four in Michigan, would close permanently. On December 13, 2022, Sears Hometown filed for Chapter 11 bankruptcy. It
16402-648: The remnants of Western Auto (which it had acquired in 1998) to Roanoke -based Advance Auto Parts . The business deal was not what experts in the after-market automotive industry expected: Sears, Roebuck became "one of the largest shareholders" after obtaining a 40% stake in Advance Auto Parts and merging their two store networks, which included Western Auto's wholesale and retail operations. The existing store network of Advance Auto Parts, comprising 915 stores in 17 U.S. states, merged with 590 U.S.-based Parts America Stores in addition to 40 Western Auto stores in
16541-422: The storekeeper's estimate of a customer's creditworthiness. Sears built an opposite business model by offering in their catalogs a larger selection of products at published prices. By 1894, the Sears catalog had grown to 322 pages, including many new items, such as sewing machines, bicycles, sporting goods and automobiles (later produced, from 1905 to 1915, by Lincoln Motor Car Works of Chicago [no relation to
16680-503: The stores the third week of December. The line won popularity with hobbyists, home users, and small businesses. Tandy Corporation's leading position in what Byte magazine called the "1977 Trinity" ( Apple Computer , Commodore , and Tandy) had much to do with Tandy's retailing the computer through more than 3,000 of its Radio Shack storefronts in the USA. Tandy claimed it had "7000 [Radio Shack] stores in 40 countries". The pre-release price for
16819-441: The term personal computer became generally used for microcomputers compatible with the IBM PC architecture ( IBM PC–compatible ). Sears Sears, Roebuck and Co. , commonly known as Sears ( / s ɪər z / SEERZ ), is an American chain of department stores founded in 1892 by Richard Warren Sears and Alvah Curtis Roebuck and reincorporated in 1906 by Richard Sears and Julius Rosenwald , with what began as
16958-452: The term " personal computer " or "PC", which specifies a computer that has been designed to be used by one individual at a time, a term first coined in 1959. IBM first promoted the term "personal computer" to differentiate the IBM PC from CP/M -based microcomputers likewise targeted at the small-business market, and also IBM's own mainframes and minicomputers. However, following its release,
17097-603: The term in his short story " The Dying Night " as early as 1956 (published in The Magazine of Fantasy and Science Fiction in July that year). Most notably, the microcomputer replaced the many separate components that made up the minicomputer's CPU with one integrated microprocessor chip . In 1973, the French Institut National de la Recherche Agronomique (INRA) was looking for a computer able to measure agricultural hygrometry . To answer this request,
17236-493: The time—styles made famous by Bertram Goodhue and Eliel Saarinen . Its stores were oriented to motorists. Set apart from existing business districts amid residential areas occupied by their target audience, they had ample, free, off-street parking and communicated a clear corporate identity. In the 1930s, the company designed fully air-conditioned, "windowless" stores, such as Sears-Pico in 1939 in Los Angeles , which
17375-526: The two men visited National Semiconductor in California in mid-1976, Homebrew Computer Club member Steve Leininger's expertise on the SC/MP microprocessor impressed them. National executives refused to provide Leininger's contact information when French and Roach wanted to hire him as a consultant, but they found Leininger working part-time at Byte Shop . Leininger was unhappy at National, his wife wanted
17514-460: The video monitor and serves as its base, was offered instead. Standard features of the E/I are a floppy disk controller, Centronics parallel port for a printer, and an added cassette connector. Optionally, an extra 16 or 32 KB of RAM can be installed and a daughterboard with an RS-232 port. The 40-conductor expansion connector passes through to a card edge connector, which permits the addition of external peripherals such as an outboard hard disk drive,
17653-399: The wall", and the first issue of 80 Micro has three articles on how to improve cassette performance. It is sensitive to audio volume, and the computer gives only a crude indication as to whether the correct volume was set, via a blinking character on screen while data is loaded. To find the correct volume at first use, the load is started and the volume is adjusted until the TRS-80 picked up
17792-493: Was a striking exception, bearing a modern design based on a monitor, keyboard, and tape and disk drives). Of the early "box of switches"-type microcomputers, the MITS Altair 8800 (1975) was arguably the most famous. Most of these simple, early microcomputers were sold as electronic kits —bags full of loose components which the buyer had to solder together before the system could be used. The period from about 1971 to 1976
17931-466: Was a successful American chain of more than 3,000 electronics stores. Among the Tandy employees who purchased a MITS Altair kit computer was buyer Don French, who began designing his own computer and showed it to the vice president of manufacturing John V. Roach , Tandy's former electronic data processing manager. Although the design did not impress Roach, the idea of selling a microcomputer did. When
18070-535: Was based on LSI chips with an Intel 8008 as peripheral controller (keyboard, monitor and printer), before adopting the Zilog Z80 as main processor. In late 1972, a Sacramento State University team led by Bill Pentz built the Sac State 8008 computer, able to handle thousands of patients' medical records. The Sac State 8008 was designed with the Intel 8008. It had a full set of hardware and software components :
18209-529: Was described in Wayne Green 's editorial in the first issue of 80 Micro . Dirt, cigarette smoke , or other contamination enters the unsealed key switches, causing electrical noise that the computer detects as multiple presses. The key switches can be cleaned, but the bounce recurs when the keyboard is reexposed to the contaminating environment. Keyboard bounce only occurs in Model I computers with Level II BASIC firmware ; Level I BASIC has
18348-474: Was easier to learn and use than raw machine language, became a standard feature. These features were already common in minicomputers , with which many hobbyists and early produces were familiar. In 1979, the launch of the VisiCalc spreadsheet (initially for the Apple II ) first turned the microcomputer from a hobby for computer enthusiasts into a business tool. After the 1981 release by IBM of its IBM PC ,
18487-518: Was handled by Albert Henry Loeb of Chicago law firm Loeb & Adler (now Arnstein & Lehr ); copies of the transaction are still displayed on the firm's walls. Sears and Rosenwald got along well with each other, but not with Nusbaum; they bought his interest in the firm for $ 1.3 million in 1903 ($ 44.1 million today). Rosenwald brought to the mail-order firm a rational management philosophy and diversified product lines: dry goods, consumer durables, drugs, hardware, furniture, and nearly anything else
18626-429: Was released in 1971. Like the Datapoint 2200, it used small-scale integrated transistor–transistor logic instead of a microprocessor. It was marketed as an educational and hobbyist tool, but it was not a commercial success; production ceased shortly after introduction. In late 1972, a French team headed by François Gernelle within a small company, Réalisations & Etudes Electroniques (R2E), developed and patented
18765-720: Was stable, the cassette load/save process combined with keyboard bounce issues and a troublesome Expansion Interface contributed to the Model I's reputation as not well-suited for serious use. Initially (until 1981), it lacked support for lowercase characters which may have hampered business adoption. An extensive line of upgrades and add-on hardware peripherals for the TRS-80 was developed and marketed by Tandy/Radio Shack. The basic system can be expanded with up to 48 KB of RAM (in 16 KB increments), and up to four floppy disk drives and/or hard disk drives . Tandy/Radio Shack provided full-service support including upgrade, repair, and training services in their thousands of stores worldwide. By 1979,
18904-428: Was the first to have an open plan selling floor (instead of breaking up the floor into discrete sections). Sears was also a pioneer in creating department stores that catered to men and women. The stores included hardware and building materials. It de-emphasized the latest clothing fashions in favor of practical and durable clothing and allowed customers to select goods without the aid of a clerk. In 1933, Sears issued
19043-436: Was the quantity the company would have to produce to buy the components in bulk. Roach persuaded Tandy to agree to build 3,500—the number of Radio Shack stores—so that each store could use a computer for inventory purposes if they did not sell. RCA agreed to supply the video monitor—a black-and-white television with the tuner and speakers removed—after others refused because of Tandy's low initial volume of production. Tandy used
19182-579: Was transformed into the new Sears Holdings Corporation . The new company started trading on the NASDAQ stock exchange as SHLD; Sears sold its single-letter ticker symbol 'S' in the New York Stock Exchange that it had held since 1910 to Sprint Corporation . The new corporation announced that it would continue to operate stores under both the Sears and Kmart brands. In 2005, the company began renovating some Kmart stores and converting them to
19321-459: Was widely sold in kit form, along with an eighth 2102 chip. Later models came with the hardware for the lowercase character set to be displayed with descenders. With higher-density RAM chips and purpose-built monitors, higher-resolution crisp displays are obtainable; 80×24-character displays are available in the Model II, Model 4, and later systems. The Model I has no built-in speaker. Square-wave tones can be produced by outputting data to
#89910