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MOS 6507
The 6507 (typically "''sixty-five-oh-seven''" or "''six-five-oh-seven''") is an 8-bit microprocessor from MOS Technology, Inc. It is a version of their 40-pin 6502 packaged in a 28-pin DIP, making it cheaper to package and integrate in systems. The reduction in pin count is achieved by reducing the address bus from 16 bits to 13 (limiting the available memory range from 64 KB to 8KB) and removing a number of other pins used only for certain applications. To do this, A15 to A13 and some other signals such as the interrupt lines are not accessible. As a result, it can only address 8KB of memory, which for some applications at the time (1975) was acceptable and not overly restrictive. The entire 6500 CPU family was originally conceived as a line of very low-cost microprocessors for small-scale embedded systems. The 6507 and 6502 chips use the same underlying silicon layers, and differ only in the final metallisation layer. This ties the interrupt lines to their inactive level so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOS Technology
MOS Technology, Inc. ("MOS" being short for Metal Oxide Semiconductor), later known as CSG (Commodore Semiconductor Group) and GMT Microelectronics, was a semiconductor design and fabrication company based in Audubon, Pennsylvania. It is most famous for its 6502 microprocessor and various designs for Commodore International's range of home computers. History Three former General Instrument executives, John Paivinen, Mort Jaffe and Don McLaughlin, formed MOS Technology in Valley Forge, Pennsylvania in 1969. The Allen-Bradley Company was looking to provide a second source for electronic calculators and their chips designed by Texas Instruments (TI). In 1970 Allen-Bradley acquired a majority interest in MOS Technology. In the early 1970s, TI decided to release their own line of calculators, instead of selling just the chips inside them, and introduced them at a price that was lower than the price of the chipset alone. Many early chip companies were reliant on sales of cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atari 1050
The Atari 1050 was a floppy disk drive for the Atari 8-bit family home computers, released in June 1983. It was compatible with the 90 kB single-density mode of the original Atari 810 it replaced, and added a new "enhanced" or "dual density" mode that provided 130 kB. Based on a half-height Tandon mechanism, it was much smaller than the 810 and matched the styling of the new 600XL and 800XL machines. By the time it was available, a wide variety of third party drives had been introduced for the 8-bit platform, many of which were faster and offered true double-density support for 180 kB. The lack of double-density support on the 1050 was a mystery to onlookers at the time, as the hardware had full support for this format. The launch was further marred by releasing it with the older Atari DOS 2.0S, S for "single", which did not support the 130 kB capacity. Atari replaced 2.0 with DOS 3.0 which supported the enhanced density mode, but used an entirely new format t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
65xx Microprocessors
The MOS Technology 65xx series is a family of 8-bit microprocessors from MOS Technology, based on the Motorola 6800 (introduced ca. 1975). The 65xx family included the 6502, used in home computers such as the Commodore PET and VIC-20, the Apple II, the Atari 800, and the British BBC Micro. The 6501 and 6502 have 40-pin DIP packages; the 6503, 6504, 6505, and 6507 are 28-pin DIP versions, for reduced chip and circuit board cost. In all of the 28-pin versions, the pin count is reduced by leaving off some of the high-order address pins and various combinations of function pins, making those functions unavailable. Typically, the 12 pins omitted are the three not connected (NC) pins, one of the two Vss pins, one of the clock pins, the SYNC pin, the set overflow (SO) pin, either the maskable interrupt or the non-maskable interrupt (NMI), and the four most-significant address lines (A12–A15) are the 12 pins omitted to reduce the pin count from 40 to 28. The omission of four addre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOS Technology Microprocessors
MOS or Mos may refer to: Technology * MOSFET (metal–oxide–semiconductor field-effect transistor), also known as the MOS transistor * Mathematical Optimization Society * Model output statistics, a weather-forecasting technique * MOS (filmmaking), term for a scene that is "motor only sync" or "motor only shot", or jokingly, “mit out sound” * Mobile operating system, operating systems for mobile devices Computing * Acorn MOS, an operating system used in the Acorn BBC computer range * Media Object Server, a protocol used in newsroom computer systems * Mean opinion score, a measure of the perceived quality of a signal * MOS (operating system), a Soviet Unix clone * My Oracle Support, a support site for the users of Oracle Corporation products, known until October 2010 as "MetaLink" *macOS, an operating system for Macs Government and military * Master of the Sword, the title for the head of physical education at the U.S. Military Academy at West Point * Member of Servic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Interface Adaptor
The Television Interface Adaptor (TIA) is the custom computer chip, along with a variant of the MOS Technology 6502 constituting the heart of the 1977 Atari Video Computer System game console. The TIA generates the screen display, sound effects, and reads the controllers. At the time the Atari VCS was designed, even small amounts of RAM were expensive. The chip was designed around not having a frame buffer, instead requiring detailed programming to create even a simple display. Development of the CO10444/CO11903 TIA was led by Jay Miner who continued at Atari expanding on the design of the TIA for the Atari 400/800 computers with the ANTIC and CTIA/GTIA chips. Jay Miner later led the design of the custom chips for the Amiga computer. Design Background Around 1975, Atari's engineers at Cyan Engineering led by Steve Mayer and Ron Milner had been considering alternatives to the development dedicated hardware such as application-specific integrated circuits (ASIC) for arcade v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-maskable Interrupt
In computing, a non-maskable interrupt (NMI) is a hardware interrupt that standard interrupt-masking techniques in the system cannot ignore. It typically occurs to signal attention for non-recoverable hardware errors. Some NMIs may be masked, but only by using proprietary methods specific to the particular NMI. An NMI is often used when response time is critical or when an interrupt should never be disabled during normal system operation. Such uses include reporting non-recoverable hardware errors, system debugging and profiling, and handling of special cases like system resets. Modern computer architectures typically use NMIs to handle non-recoverable errors which need immediate attention. Therefore, such interrupts should not be masked in the normal operation of the system. These errors include non-recoverable internal system chipset errors, corruption in system memory such as parity and ECC errors, and data corruption detected on system and peripheral buses. On some systems, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt Request (PC Architecture)
In a computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Hardware interrupts are used to handle events such as receiving data from a modem or network card, key presses, or mouse movements. Interrupt lines are often identified by an index with the format of ''IRQ'' followed by a number. For example, on the Intel 8259 family of programmable interrupt controllers (PICs) there are eight interrupt inputs commonly referred to as ''IRQ0'' through ''IRQ7''. In x86 based computer systems that use two of these PICs, the combined set of lines are referred to as ''IRQ0'' through ''IRQ15''. Technically these lines are named ''IR0'' through ''IR7'', and the lines on the ISA bus to which they were historically attached are named ''IRQ0'' through ''IRQ15'' (although historically as the number of hardware devices increased, the total possible number of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor
A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glass. Its electrical resistivity and conductivity, resistivity falls as its temperature rises; metals behave in the opposite way. Its conducting properties may be altered in useful ways by introducing impurities ("doping (semiconductor), doping") into the crystal structure. When two differently doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions is the basis of diodes, transistors, and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second-most common s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Read-only Memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware. Software applications (like video games) for programmable devices can be distributed as plug-in cartridges containing ROM. Strictly speaking, ''read-only memory'' refers to memory that is hard-wired, such as diode matrix or a mask ROM integrated circuit (IC), which cannot be electronically changed after manufacture. Although discrete circuits can be altered in principle, through the addition of bodge wires and/or the removal or replacement of components, ICs cannot. Correction of errors, or updates to the software, require new devices to be manufactured and to replace the installed device. Floating-gate ROM semiconductor memory in the form of erasab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOS Technology 650x
The MOS Technology 65xx series is a family of 8-bit microprocessors from MOS Technology, based on the Motorola 6800 (introduced ca. 1975). The 65xx family included the 6502, used in home computers such as the Commodore PET and VIC-20, the Apple II, the Atari 800, and the British BBC Micro. The 6501 and 6502 have 40-pin DIP packages; the 6503, 6504, 6505, and 6507 are 28-pin DIP versions, for reduced chip and circuit board cost. In all of the 28-pin versions, the pin count is reduced by leaving off some of the high-order address pins and various combinations of function pins, making those functions unavailable. Typically, the 12 pins omitted are the three not connected (NC) pins, one of the two Vss pins, one of the clock pins, the SYNC pin, the set overflow (SO) pin, either the maskable interrupt or the non-maskable interrupt (NMI), and the four most-significant address lines (A12–A15) are the 12 pins omitted to reduce the pin count from 40 to 28. The omission of four addre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory-mapped I/O
Memory-mapped I/O (MMIO) and port-mapped I/O (PMIO) are two complementary methods of performing input/output (I/O) between the central processing unit (CPU) and peripheral devices in a computer. An alternative approach is using dedicated I/O processors, commonly known as channels on mainframe computers, which execute their own instructions. Memory-mapped I/O uses the same address space to address both main memory and I/O devices. The memory and registers of the I/O devices are mapped to (associated with) address values. So a memory address may refer to either a portion of physical RAM, or instead to memory and registers of the I/O device. Thus, the CPU instructions used to access the memory can also be used for accessing devices. Each I/O device monitors the CPU's address bus and responds to any CPU access of an address assigned to that device, connecting the data bus to the desired device's hardware register. To accommodate the I/O devices, some areas of the address bus use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
