The 6800 (" sixty-eight hundred ") is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor is part of the M6800 Microcomputer System also includes serial and parallel interface IC, RAM, ROM and other support chips. A significant design feature is that the IC M6800 family requires only a five volt supply power when most other microprocessors require three voltages. The M6800 Microcomputer system was announced in March 1974 and started full production by the end of that year.
6800 has a 16-bit address bus that can access 64 kB of memory directly and 8-bit bi-directional data bus. It has 72 instructions with seven addressing modes for a total of 197 opcodes. The original MC6800 could have clock frequency up to 1 MHz. The newer version has a maximum clock frequency of 2 MHz.
In addition to IC, Motorola also provides a complete assembly language development system. Customers can use the software on a remote timeshare computer or on a mini computer system at home. Motorola EXORciser is a desktop computer made with the M6800 IC that can be used to create new design prototypes and debugs. Extensive documentation packages include data sheets on all ICs, two assembly language programming guides, and a 700 page application manual that shows how to design a point-of-sale computer terminal.
The 6800 is popular on computer peripherals, test equipment apps and terminal point-of-sale. It was also found used in arcade games and pinball machines. The MC6802, introduced in 1977, included 128 bytes of RAM and an internal clock oscillator on the chip. The MC6801 and MC6805 included with RAM, ROM and I/O on one chip are popular in automotive applications.
Video Motorola 6800
Histori
Sejarah Motorola dalam semikonduktor
Galvin Manufacturing Corporation was founded in 1928; the company's name was changed to Motorola in 1947. They started commercial production of transistors at a new facility valued at $ 1.5 million in Phoenix in 1955.
Motorola transistors and integrated circuits are used alone for communications, military, automotive and consumer products and they are also sold to other companies. In 1973, the Semiconductor Products Division (SPD) had sales of $ 419 million and was the second largest semiconductor company after Texas Instruments.
In the early 1970s Motorola started a project that developed their first microprocessor, the MC6800. This is followed by a single chip microcontroller such as MC6801 and MC6805.
Development team
Motorola has not recorded the development of the 6800 microprocessor as Intel did for their microprocessors. In 2008, the Computer History Museum interviewed four members of the 6800 microprocessor design team. Their recordings can be confirmed and expanded by magazine articles and journals written at the time.
The Motorola microprocessor project began in 1971 with teams comprising designers Tom Bennett, technical director Jeff LaVell, Link Young product marketers and system designers Mike Wiles, Gene Schriber and Doug Powell. They are all in Mesa, Arizona. By the time the project was completed, Bennett had 17 chip designers and people working on five chips. LaVell has 15 to 20 system engineers and there are other application engineering groups of the same size.
Tom Bennett has a background in industrial control and has worked for Victor Comptometer in the 1960s designing the first electronic calculator to use the MOS IC, the Victor 3900. In May 1969, Ted Hoff showed Bennett the initial diagram of Intel 4004 to see if it would meet the needs of the calculator they. Bennett joined Motorola in 1971 to design an IC calculator. He was soon commissioned as the principal architect of the microprocessor project that produced 6800. The others had taken credit for designing the 6800. In September 1975 Robert H. Cushman, editor of the EDN magazine microprocessor, interviewed Chuck Peddle about the new MOS Technology 6502 microprocessor. Cushman then asked "Tom Bennett, the principal architect of the 6800," to comment on this new competitor. After 6800 the Bennett project worked on automotive applications and Motorola became the leading supplier of microprocessors used in cars.
Jeff LaVell joined Motorola in 1966 and worked in the computer industry marketing organization. Jeff previously worked for Collins Radio on their C8500 computer that was built with small scale ECL ICs. In 1971 he led a group that examined the needs of their existing customers such as Hewlett Packard, National Cash Register, Control Data Corporation (CDC), and Digital Equipment Corporation. They will study customer products and try to identify functions that can be implemented in larger integrated circuits at a lower cost. The survey results are a family of 15 building blocks; each can be implemented in integrated circuits. Some of these blocks are implemented in early M6800 releases and more are added over the next few years. To evaluate the 6800 architecture while the chip was being designed, Jeff's team built an equivalent circuit using 451 small TTL ICs at five 10 by 10 inch (25 by 25 cm) circuit boards. Then they reduce this to 114 ICs on a single board using ROM and MSI logic devices (intermediate integration).
John Buchanan is a memory designer at Motorola when Bennett asked him to design a voltage doubler for 6800. Typical n-channel MOS ICs require three power supplies: -5 volts, 5 volts, and 12 volts. The M6800 family only uses one, 5 volts. It's easy to eliminate the supply of -5 volts but the MOS transistors require a 10 to 12 volt supply. This voltage doubler on-chip will supply higher voltage and Buchanan do circuit design, analysis and layout for 6800 microprocessor. He received a patent on voltage doubler and 6800 chip layout. Rod Orgill helped Buchanan with an analysis and 6800 chip layout. Later Orgill will design the MOS Technology 6501 microprocessor compatible with the 6800 socket.
Bill Lattin joined Motorola in 1969 and his group provided computer simulation tools to characterize the new MOS circuitry in 6800. Lattin and Frank Jenkins had attended UC Berkeley and studied computer circuit simulators under Donald Pederson, SPICE circuit simulator designer. The Motorola simulator, MTIME, is an advanced version of the TIME simulator circuit developed by Jenkins in Berkeley. The group published a technical paper, "modeling MOS-devices for computer implementations" in 1973 describing "5-V single-supply n-channel technology" operating at 1 MHz. They can simulate 50 MOSFET circuits on IBM 370/165 mainframe computer. In November 1975, Lattin joined forces with Intel to work on the next generation of microprocessors.
Bill Mensch joined Motorola in 1971 after graduating from the University of Arizona. He has worked for several years as an electronic technician before earning a BSEE degree. The first year at Motorola is a series of three-month rotations through four different areas. Mensch does a flowchart for the modem which will become 6860. He also works the application group that defines the M6800 system. After this year of training, he was assigned to the 6820 Network Interface Adjustment (PIA) development team. Mensch is a major contributor to the design of this chip and received a patent on IC layout and named as co-inventor of seven other M6800 system patents. Then Mensch will design the MOS Technology 6502 microprocessor.
Mike Wiles is a design engineer in the Jeff LaVell group and conducts numerous customer visits with Tom Bennett during the 6800-phase product definition. He is listed as the inventor on eighteen 6800 patents but is best known for his computer program, MIKBUG. It is a monitor for 6800 computer systems that allows users to check the contents of RAM and save or load programs to tape. This 512 byte program occupies half of the MCM6830 ROM. This ROM is used in the Motorola MEK6800 design evaluation kit and the early hobby computer kit. Wiles lived with Motorola, moved to Austin and helped design the MC6801 microcontroller released in 1978.
Chuck Peddle joined the design team in 1973 after the design of the 6,800 processor was done but he contributed to the overall system design and some device chips, especially the 6820 parallel interface (PIA). Peddle is listed as the inventor on sixteen Motorola patents, most of which have six or more co-inventors. Like other engineers on the team, Peddle visits potential customers and asks for their input. Peddle and John Buchanan built one of the 6800 early demonstration boards. In August 1974 Chuck Peddle left Motorola and joined a small semiconductor company in Pennsylvania, MOS Technology. There he led a team that designed 6500 family microprocessors.
MC6800 microprocessor design
Motorola 6800 and Intel 8080 are designed at the same time and function similar. 8080 is an extension and upgrade of the Intel 8008, which in turn is an LSI implementation of the TTL-based CPU design used in the Datapoint 2200. The 6800 architecture is modeled after the DEC PDP-11 processor. Both the 8080 and 6800 are TTL compatible, have an 8-bit bidirectional data bus, 16-bit stack pointer, 16-bit address bus that can handle 64 kB of memory, and come in a 40-pin DIP package. The 6800 has two accumulators and a 16-bit index register. Direct addressing mode allows fast access to the first 256 bytes of memory. The I/O device is intended as memory so there is no special I/O instruction. 8080 has more internal registers and instructions for special I/O ports. When 8080 is reset, the program counter is deleted and the processor starts at the memory location 0000. 6800 loads the program counter from the highest address and starts at the memory location stored there. 6800 has a three-state control that will disable the address bus to allow other devices to access the memory directly. Therefore the disk controller transfers the data into memory without any load on the processor. It is even possible to have two 6800 processors accessing the same memory. However, in practice such complexity systems typically require the use of an external bus transceiver to drive the system bus; in such circuits, the processor bus control is disabled completely because it uses a similar bus transceiver capability. Instead, the 6802 is given full on-chip control to free the pins for other functions in a 40-pin package equal to 6800, but this function can still be achieved by using an external bus transceiver.
MOS ICs typically use double clock signals (two phase clocks) in the 1970s. It's generated externally for both the 6800 and 8080. The next generation of microprocessors combines clock generation on the chip. The 8080 has a 2 MHz clock but the processing throughput is similar to 1 MHz 6400, since the 8080 takes more clock cycles to execute processor instructions than the 6800. The 6800 has a clock rate of at least 100 kHz, while the 8080 has no lower limit and can be stopped (effectively clock speed 0 Hz). High-speed versions of both microprocessors were released in 1976.
Another division at Motorola developed components for the M6800 family. The Product Components department designs MC6870 phase two phase ICs, and the Memory Products group provides a full line of ROM and RAM. MC14411 Bit Rate Generator from CMOS group provides 75 to 9600 baud clock for MC6850 serial interface. Buffers for address and data bus are Motorola's standard products. Motorola can provide every IC, transistor, and diode needed to build an MC6800 based computer.
IC MOS
First generation metal-oxide-semiconductor (MOS) chip uses p-channel field effect transistor, known as p-channel MOSFET (p-channel describes transistor configuration). These ICs are used in calculators and in the first microprocessor, Intel 4004. They are easy to manufacture but are slow and difficult to connect to popular TTL digital logic ICs. An integrated MOS n-channel circuit can operate two or three times faster and is compatible with TTL. They are much more difficult to produce due to increased sensitivity to contamination requiring ultra clean production lines and careful process control. Motorola does not have the n-channel MOS production capability and should expand it to 6800 families.
The integrated circuit of the Motorola MOS test circuit was completed in late 1971 and this shows that the clock rate will be limited to 1 MHz. This "enhancement-mode" MOS transistor is used. There are newer fabrication technologies that use "MOS Depletion-Mode" transistors as loads, which will allow smaller and faster circuits (this is also known as load-depletion nMOS). The "depletion-mode" process requires additional steps so Motorola decides to keep using "additional mode" for the new single supply voltage design. The clock rate of 1 MHz means that the chip designers must come up with some architectural innovation to speed throught the microprocessor. The resulting circuit is faster but requires more area on the chip.
In the 1970s, semiconductors were made on silicon wafers of diameter 3 inches (75 mm). Each wafer can produce 100 to 200 integrated circuit chips or die. The technical literature will state the length and width of each chip in "miles" (0.001 inches). The size of the Intel 8080 microprocessor chip is 164 mils x 191 mils (4.1 mm x 4.9 mm). Current industry practice is to declare chip area so chip size 8080 will be 19.7 mm 2 .
Wafer processing requires many steps and deficiencies will appear in various locations on the wafer during each step. The larger the chips the more likely it will be defective. The percentage of chips or work begins to decline for chips larger than 160 mils (4 mm) on the side. The target size for 6800 is 180 mil (4.6 mm) on each side but the final size is 212 mils (5.4 mm) wide (29.0 mm 2 ). At 180 miles, a 3 inch (76 mm) wafer will store about 190 chips, 212 mils reducing it to 140 chips. At this size, the result may be 20% or 28 chips per wafer. The Motorola 1975 annual report highlights the new MC6800 microprocessor but has several paragraphs about "Problem MOS results." The result issue was resolved with a design revision beginning in 1975 to use depletion mode in the M6800 family device. The size of the 6800 die is reduced to 160 mils (4 mm) per side with an area of ​​16.5 mm 2 . It also allows faster clock speeds, MC68A00 will operate at 1.5 MHZ and MC68B00 at 2.0 MHz. New parts are available in July 1976.
introduction of M6800 family
The March 7, 1974 edition of Electronics has a two-page story on the Motorola MC6800 microprocessor along with the MC6820 Peripheral Interface Adapter, MC6850 adapter communication interface, MCM6810 128 byte RAM and MCM6830 1024 byte ROM. This was followed by an eight-page article in the April 18, 1974 edition written by the Motorola design team. This issue also has articles introducing Intel 8080
The Intel 8080 and Motorola MC6800 processors began operations around December 1972. The first 8080 chip was produced in January 1974 and the first public announcement was in February 1974. 8080 uses three NOS channels of the same MOS voltage as the existing Intel memory chips allow production full to start the April.
The first MC6800 chip that was manufactured was manufactured in February 1974 and engineering samples were given to selected customers. Hewlett Packard in Loveland, Colorado wants the MC6800 for a new desktop calculator and has a prototype system that works in June. MC6800 uses a single voltage single channel MOS process that proves very difficult to implement. The M6800 microcomputer system was finally manufactured in November 1974. Motorola matches Intel's price for a single microprocessor, $ 360. (The IBM/360 system is today's well-known computer.) In April 1975, the MEK6800D1 microcomputer design package was offered for $ 300. six chips in the M6800 family plus application and programming manuals. The price of one microprocessor MC6800 is $ 175.
Link Young is a product marketer who developed a total system approach for the M6800 family release. In addition to releasing a full set of support chips with a 6800 microprocessor, Motorola offers software and hardware development systems. Software development tools are available on remote share time computers or source code is available so customers can use home computer systems. Software that will run on a microprocessor system is usually written in assembly language. The development system consists of a text editor, assembler and simulator. This allows developers to test the software before the target system is complete. Hardware development is a desktop computer built with the M6800 family CPU and peripherals known as EXORcisor. Motorola offers microprocessor design courses for three to five days for 6800 hardware and software. This system-oriented approach becomes the standard way new microprocessors are introduced.
Design team relation
The main design effort on the M6800 family was completed in mid-1974, and many engineers left the group or company. Several factors led to the breakup of the design group.
Motorola has opened a new MOS semiconductor facility in Austin Texas. The entire engineering team was scheduled to move there in 1975. Many employees like to live in Phoenix suburbs in Mesa and are very careful to move to Austin. Team leaders were unsuccessful with their application to senior management to delay the move.
A recession hit the semiconductor industry in mid-1974 which resulted in thousands of layoffs. November 1974 Magazine Electronics magazine reports that Motorola has laid off 4,500 employees, Texas Instruments 7,000 and Signetics 4,000. Motorola's Semiconductor Product Division will lose thirty million dollars in the next 12 months and there are rumors that the IC group will be sold. Motorola does not sell divisions but they change management and organization. At the end of 1974, Intel fired nearly a third of its 3,500 employees. The MOS IC business rebounded but job security was not taken for granted in 1974 and 1975.
Chuck Peddle (and other Motorola engineers) have been visiting customers to explain the benefits of microprocessors. Both Intel and Motorola initially set the price of one microprocessor for $ 360. Many customers are hesitant to adopt this new microprocessor technology with high price tags. (The actual price for production quantities is much lower.) In mid-1974, Peddle proposed a simplified microprocessor that could be sold for a much lower price. Motorola's "total product family" strategy does not focus on MPU prices but on total customer cost reduction. Their immediate goal was to complete the system they completed and they would work for improvement in 1975.
Peddle continues to work for Motorola while looking for investors to conceptualize his new microprocessor. In August 1974 Chuck Peddle left Motorola and joined a small semiconductor company in Pennsylvania, MOS Technology. He was followed by seven other Motorola engineers: Harry Bawcum, Ray Hirt, Terry Holdt, Mike James, Will Mathis, Bill Mensch, and Rod Orgill. The Peddle group at MOS Technology developed two new microprocessors compatible with Motorola peripheral chips like the 6820 PIA. Rod Orgill designed the MCS6501 processor that will be plugged into the MC6800 socket and Bill Mensch performing the MCS6502 which has a series of clock generation on the chip. These microprocessors will not run 6800 programs because they have different architectures and instruction sets. The ultimate goal is a microprocessor that will sell for under $ 25. This will be done by removing non-essential features to reduce chip size. An 8-bit stack pointer is used instead of a 16-bit. The second accumulator is removed. The address buffer does not have a three-state mode for Direct Memory Access (DMA) data transfer. The goal is to get chip size up to 153 mils x 168 mils (3.9 mm x 4.3 mm).
Chuck Peddle is a very effective spokesperson and MOS Technology's microprocessors are extensively covered in the trade press. One of the earliest was a full-page story on the MCS6501 and MCS6502 microprocessors in the July 24, 1975 issue of the Electronics magazine. The stories also appear on EE Times (August 24, 1975), EDN (September 20, 1975), Electronic News (November 3, 1975) and < i Byte (November 1975). Advertisements for 6501 appeared in several publications in the first week of August 1975. 6501 will be sold at the WESCON trade show in San Francisco, September 16-19, 1975, respectively for $ 20. In September 1975, advertisements included 6501 and 6502 microprocessors. The 6502 will only cost $ 25.
Motorola responded to a $ 20 MOS Technology microprocessor immediately reducing the price of a 6800 microprocessor unit from $ 175 to $ 69 and then sued MOS Technology in November 1975. Motorola claims that the eight former Motorola engineers use technical information developed at Motorola in 6501 microprocessor design and 6502. Other MOS Technology businesses, chip calculators, declined due to price wars with Texas Instruments so their financial supporters, Allen-Bradley, decided to limit the possible losses and sell MOS Technology assets back to the founders. The suit was settled in April 1976 with MOS Technology dropping 6501 chips which will be plugged into the Motorola 6800 socket and licensed Motorola's peripheral chip. Motorola reduced the price of one unit from 6800 to $ 35.
MOS vs Motorola's suing technology has been developing the narration of David and Goliath for years. One thing is that Motorola has no patent on the technology. This was technically true when the lawsuit was filed in late 1975. On October 30, 1974, before the 6800 was released, Motorola filed numerous patent applications on the microprocessor family and was awarded over twenty patents. The first was Tom Bennett on June 8, 1976 for 6800 internal address buses. The second was for Bill Mensch on July 6, 1976 for the 6820 chip layout. Many of these patents mention several engineers who set out as co-inventors. This patent covers 6800 buses and how the peripheral chips are connected to the microprocessor. (Intel has a similar incident.) Federico Faggin, who led the development of Intel's first microprocessor, 4004, and the latest, 8080, became agitated under management changes at Intel.Faggin and other Intel engineers Ralph Ungermann began Speaking about starting their own microprocessor company , Faggin and Ungermann left Intel and started Zilog in November 1974. Masatoshi Shima, designer of the Intel 8080, joined Zilog in February 1975 and they obtained funding from Exxon's venture capital group in June 1975. Zilog decided to create a superset of Intel 8080 which also combining features of the 6800 and others.Z80 requires only a single 5 volt supply and single phase phase input.This is the first microprocessor to offer built-in support for dynamic RAM.)
Move to Austin
Gary Daniels designed the IC for electronic watches when Motorola turned off their Watch Electronics Unit. Tom Bennett offered him a job in the microprocessor group in November 1974. Bennett did not want to leave the Phoenix area so Gary Daniels set up a microprocessor development in Austin. (Daniels is the microprocessor design manager for the next ten years before he is promoted to vice president.)
The first task is to redesign the 6800 MPU to improve production output and operate at a faster hour. This design uses deplesion-mode technology and is known internally as MC6800D. The transistor count goes from 4000 to 5000 but the dead area is reduced from 29.0 mm 2 to 16.5 mm 2 . Maximum clock rate for selected components doubled to 2 MHz. Other chips in the M6800 family are also redesigned to use depletion mode technology. The Peripheral Interface Adapter has a slight change in the electrical characteristics of the I/O pin so that the MC6820 becomes MC6821. The new IC was completed in July 1976.
A new cheap generator clock generator, the MC6875, was released in 1977. It replaced the hybrid IC MC6870 for $ 35. The MC6875 comes in a 16-pin dip package and can use quartz crystal or resistor capacitor networks.
Another project combines 128 bytes of RAM and a clock generator on a single chip of 11,000 transistors. The MC6802 microprocessor was released in March 1977. The MC6846 companion chip has 2048 bytes of ROM, 8-bit bidirectional ports and a programmable timer. This is a two chip microcomputer. The 6802 has an on-chip oscillator that uses 4 quartz crystal, an external MHz to generate two 1 MHz clock phases. 128 bytes of internal RAM can be disabled by grounding pins and devices with damaged RAM sold as MC6808.
A series of peripheral chips was introduced in 1978. The MC6840 programmable counter has three 16-bit binary counters that can be used for frequency measurement, event counting, or interval measurements. MC6844 Direct Memory Access Controller can transfer data from I/O controller to RAM without loading MC6800 microprocessor. MC6845 CRT Controller provides control logic for computer-based terminal characters. The 6845 has support for a light pen, an alternative to computer mouse. This is a very popular chip and was even used on the IBM PC Monochrome Display Original Adapter with an Intel 8088 16-bit microprocessor in 1981, and in the advanced IBM Color Graphics Adapter for the original PC and its successors; IBM Enhanced Graphics Adapter cards contain custom IBM chips that emulate the Motorola 6845, with little difference.
MC6801 is a single chip microcomputer with a 6802 CPU with 128 bytes of RAM, 2RB ROM, 16-bit timer, 31 programmable parallel I/O paths and serial port. It can also use I/O lines as data and bus addresses to connect to standard M6800 peripherals. 6801 will run the 6800 code but has ten additional instructions and the execution time of the key instruction is reduced. Two 8-bit accumulators can act as single 16-bit accumulators for addition, multiple precision multiplication and multiplication. Originally designed for automotive use with General Motors as a major customer. The first app was a travel computer for Cadillac Seville 1978. This 35,000 transistor chip is too expensive for widespread adoption in a car so the function of a single MC6805 reduced-chip microcomputer is designed.
MC6809 is the most advanced 8-bit microprocessor manufactured by Motorola. It has a new instruction set similar to 6800 but abandoned op-code compatibility to improve performance and high level language support; both are compatible software in the assembler that can (and generally) produce code equivalent to 6800 opcodes not directly imitated by 6809. In this case, 6809 is upwards compatible with the 6800. The 6809 has many 16-bit operations, including the first 8-bit repetition instruction (yielding 16 bit products) in the microprocessor, two 16-bit index register and stack pointer, and full support for both independent positions (object code can run wherever it is loaded in memory) and reentrant ( object code can be written for reuse by other routines), this last feature was previously only seen on a much larger machine like the IBM 360 mainframe.
Motorola spin-off company
In 1999 Motorola spewed analog IC, digital IC and transistor business as ON Semiconductor based in Phoenix, Arizona.
In 2004 they separated their microprocessor business as Freescale Semiconductor based in Austin, Texas.
Maps Motorola 6800
Use on personal computer
MITS Altair 8800, the first successful personal computer, used the Intel 8080 microprocessor and was featured on the January 1975 cover of Popular Electronics . The first personal computer using the Motorola 6800 was introduced in late 1975. Sphere Corporation of Bountiful, Utah ran a quarter-page advertisement in the July 1975 issue of Radio-Electronics for a $ 650 USD computer kit with a microprocessor 6800, 4 kilobytes RAM, video boards and keyboards. This will display 16 lines of 32 characters on a TV or monitor. The Sphere computer kit began shipping in November 1975. The Southwest Technical Products Corporation of San Antonio, Texas, officially announced their SWTPC 6800 Computer System in November 1975. Wayne Green visited SWTPC in August 1975 and described the SWTPC computer device complete with photographs that functioned system in the October 1975 edition of 73 . The SWTPC 6800 is based on the Motorola MEK6800 chip design evaluation kit and uses MIKBUG ROM Software. MITS Altair 680 is on the cover of November 1975's Popular Electronics. The Altair 680 uses a 6800 microprocessor and, unlike the SWTPC engine, also has a front panel with toggle switches and LEDs. The initial design should be revised and the first delivery of the Altair 680B was in April 1976.
Sphere is a small startup company and has difficulties in sending all the products they declare. They filed for Chapter 11 bankruptcy in April 1977. Altair 680B was very popular but MITS focused most of its resources on their Altair 8800 computer system and they quit the hobby market in 1978. Southwest Computer Product Technical is the most successful 6800-based personal computer. Other companies, for example, Smoke Signal Broadcasting (California), Gimix (Chicago), Midwest Scientific (Olathe, Kansas), and Helix Systems (Hazelwood, Missouri), began to produce boards that are compatible with the SWTPC 6800 bus and complete systems. The Technical Systems Consultant West Lafayette, Indiana, provides ribbon-based software for 6800 (and later 6809) computers based and, once disk systems become available, operating systems and disk software as well. The 8080 system is much more popular than the 6800.
The Tektronix 4051 Graphics Computing System was introduced in October 1975. It is a professional desktop computer that has 6800 microprocessors with up to 32 kB user RAM, 300 kB of magnetic tape storage, BASIC in ROM and 1024 by 780 graphic display. The Tektronix 4051 sells for $ 7000, higher than a personal computer using the 6800.
The 6800 processor is also used in MP1000 APF game console.
The architecture and instruction set of the 6800 is easy for beginners to understand and Heathkit develops microprocessor courses and trainers ET3400 6800. Courses and coaches are proving popular among individuals and schools.
The next-generation 8-bit microprocessor architecture Motorola, MC6809 (1979), is not a binary code compatible with the 6800, but most assembly codes will assemble and run on 6809; 6800 family peripheral chips work as a matter of course.
Sample code
The following 6800 assembler source code for a subroutine named memcpy copies the byte data block from the given size from one location to another. The data block is copied one byte at a time, from the lowest address to the highest.
This example illustrates well the crippling effect that the lack of a processor of a sufficient number of registers on performance. Indeed, this processor architecture presents an extreme example of this weakness. Due to this issue and the fact that this routine needs to update two active memory addresses, the dominant part of code time is dealing with values ​​that randomize between registers and memory.
Peripherals
List of "Motorola Microcomputer Components", November 1978
Second Source
The general requirement for a manufacturing company is to require two or more sources for each part of the product they produce. This ensures they can get spare parts if the supplier has financial or disaster problems. Motorola initially chose American Microsystems Inc (AMI) (ironically since 2008 part of ON Semiconductor, Motorola's semiconductor business that spun in 1999) as the second source for the M6800 family. Hitachi, Fujitsu, Fairchild, Rockwell and Thomson Semiconductors were added later.
Rochester Electronics Official by Freescale/Motorola in 2014 to continue to produce 8-bit devices and 8-bit processors in this era. Rochester specializes in fully authorized device duplications. Freescale has provided all source design archives to enable Rochester Electronics for this and other products. By the end of 2016, Rochester is fully qualified and sends MC6802, MC6840 PIA, and MC6809 processors (including MC68A09 and MC68B09 versions) and can still be purchased today.
Oral history
- "Intel 8080 Microprocessor Oral History Panel" Steve Bisset, Federico Faggin, Hal Feeney, Edward Gelbach, Ted Hoff, Stan Mazor, Masatoshi Shima, Museum of Computer History, April 26, 2007, moderator: David House.
- "Zilog Z80 Microprocessor Oral History Panel" Federico Faggin, Masatoshi Shima, Ralph Ungermann, Ralph Ungermann. Computer History Museum, April 27, 2007, moderator: Michael Slater.
- "Motorola 6800 Oral History Panel" Thomas H. Bennett, John Ekiss, William (Bill) Lattin, Jeff Lavell. Museum of Computer History, March 28, 2008, moderator: David Laws.
- Interview with William Mensch Stanford and Silicon Valley Project, 9 October 1995. Transcript
See also
- EXORmacs, follow up system for M68000 processor
References
External links
- MC6800 manual application from 1975 - lots of information
- MDOS User Manual
- Motorola Exorciser Emulator for Windows
- Open source Motorola Exorciser and SWTPC emulator for Linux/Cygwin
- MIKBUG
- 680x image and description in cpu-collection.de
- Summary instruction set
- Java Applet Simulator from simplified M6800 microprocessor
- Visual 6800 in JavaScript - transistor level graphic simulator
Source of the article : Wikipedia
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