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.[3] The reduction in pin count is achieved by reducing the address bus from 16 bits to 13 (limiting the available memory range from 64KB to 8KB) and removing a number of other pins used only for certain applications.[4]
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.[5]
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 they are not vulnerable to generating spurious interrupts from noise. The first three digits of the chip identifier are part of the silicon layers, and the final digit is in the metallisation layer. Micro-photography of the 6502 and 6507 shows this difference.[6]
The Atari 2600 contains a 6507 as one of its three main chips.
The 6507 is widely used in two applications: the best-selling Atari 2600video game console[7] and Atari 8-bit family peripherals including the 850 Serial & Parallel Interface,[8] and the 810 and 1050 disk drives.[9][10] In the 2600, the system is further limited by the design of the ROM cartridge slot, which allows for 4KB of external memory to be addressed. The other 4KB is reserved for the internal RAM and I/O chips, using a minimal-cost partial decoding technique that causes the RAM and peripheral device registers to appear at multiple aliased addresses throughout the 4K address space.[11]
Most other machines, notably home computers based on the 6500 architecture, use either the standard 6502 or extended versions of it, in order to allow for more memory.
By the time the 6502 line was becoming widely used around 1980, ROM and RAM semiconductor memory prices had fallen to the point where the 6507 was no longer a worthwhile simplification. Its use in new designs ceased at that point, though the Atari 2600 that contains it continued to be sold into the early 1990s, as it was not discontinued until January 1, 1992. However, late-model Atari 2600 consoles do not necessarily contain a discrete 6507 chip.
The 6507 uses a 28-pin configuration, with 13 address pins and 8 data pins. The seven remaining pins are used for power, the CPU timing clock, to reset the CPU, to request a CPU wait state during its next memory read access (the RDY pin), and for the CPU to indicate if a read or write memory (or MMIO device) access is being performed. There is no IRQ or NMI pin on the processor.
The RDY pin is not included on all other 28-pin cut-down versions of the 6502. Within the Atari 2600, RDY is used to synchronise the CPU to the television video lines. This function is essential for the 'racing the beam' method used by the 6502 and Atari Television Interface Adaptor chip to generate the television video signal.[13] In response to a specific address access, the TIA will assert RDY to halt the CPU until the end of the current video scan line.[14]
References
^"The MOS 6502 and the Best Layout Guy in the World". swtch.com. 2011-01-03. Retrieved 2014-08-09.
^Bagnall, Brian. Commodore. Variant Press. We sold a microprocessor, RAM, ROM, and I/O chip all for twelve bucks, ...
^Bagnall, Brian. Commodore. Variant Press. The 6507, which was a subset of [the 6502], could be made at a cheaper price. It was designed to be a really small package.
^"Oral History of Charles Ingerham "Chuck" Peddle" (PDF). June 12, 2014. p. 58. Retrieved 2021-05-30. You don't use a 68000 as a logic replacement; you use it as a computer. And that's a different architecture. And we weren't capable of going there, without a major investment, ... It's supposed to have been in every cash register, it's supposed to have been in every intelligent thing on the airplane, it was supposed to be everywhere.{{cite web}}: CS1 maint: url-status (link)
^"Atari 850 Interface Module Field Service Manual". Internet Archive. 1981. Retrieved 2021-06-03. Block Diagram{{cite web}}: CS1 maint: url-status (link)
^"Atari 810 Disk Drive Field Service Manual". Internet Archive. 1980. Retrieved 2021-06-03. Block Diagrams And Schematics{{cite web}}: CS1 maint: url-status (link)
^"Service Manual For The Atari 1050 Disk Drive". Internet Archive. 1983. Retrieved 2021-06-03. Electronic Theory{{cite web}}: CS1 maint: url-status (link)
^Miner, Jay (October 22, 1976). "TIA 1A – Television Interface Adaptor (Model 1A)". Internet Archive. from the original on 2008-04-24. Retrieved 2021-06-04. This circuit operates on a "line by line" basis, always outputing the same information every television line unless new data is written into it by the microprocessor.
^Wright, Steve; May, Darryl (1988). "2600 (STELLA) Programmer's Guide". Internet Archive. Retrieved 2021-06-01. Simply writting [sic] to WSYNC causes the microprocessor to halt until the electron beam reaches the right edge of the screen, ...
Further reading
Commodore Semiconductor Group: 6500 Microprocessors 2020-10-01 at the Wayback Machine, November 1985, p. 11.
technology, 6507, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, december,. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources MOS Technology 6507 news newspapers books scholar JSTOR December 2009 Learn how and when to remove this template message 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 3 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 8 KB and removing a number of other pins used only for certain applications 4 MOS Technology 6507General informationLaunched1975 48 years ago 1975 Common manufacturer s MOS TechnologyPerformanceData width8Address width13Architecture and classificationInstruction set6502Instructions56Physical specificationsTransistors3 510 1 3 218 2 Package s 28 pin DIPHistoryPredecessorMotorola 6800 MOS 6501 6502To do this A15 to A13 and some other signals such as the interrupt lines are not accessible As a result it can only address 8 KB 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 5 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 they are not vulnerable to generating spurious interrupts from noise The first three digits of the chip identifier are part of the silicon layers and the final digit is in the metallisation layer Micro photography of the 6502 and 6507 shows this difference 6 The Atari 2600 contains a 6507 as one of its three main chips The 6507 is widely used in two applications the best selling Atari 2600 video game console 7 and Atari 8 bit family peripherals including the 850 Serial amp Parallel Interface 8 and the 810 and 1050 disk drives 9 10 In the 2600 the system is further limited by the design of the ROM cartridge slot which allows for 4 KB of external memory to be addressed The other 4 KB is reserved for the internal RAM and I O chips using a minimal cost partial decoding technique that causes the RAM and peripheral device registers to appear at multiple aliased addresses throughout the 4 K address space 11 Most other machines notably home computers based on the 6500 architecture use either the standard 6502 or extended versions of it in order to allow for more memory By the time the 6502 line was becoming widely used around 1980 ROM and RAM semiconductor memory prices had fallen to the point where the 6507 was no longer a worthwhile simplification Its use in new designs ceased at that point though the Atari 2600 that contains it continued to be sold into the early 1990s as it was not discontinued until January 1 1992 However late model Atari 2600 consoles do not necessarily contain a discrete 6507 chip Pin configuration EditPin layout of MOS 6507 12 RES 1 28 Ph2 outVss 2 27 Ph0 inRDY 3 26 R WVcc 4 25 D0A0 5 24 D1A1 6 23 D2A2 7 22 D3A3 8 21 D4A4 9 20 D5A5 10 19 D6A6 11 18 D7A7 12 17 A12A8 13 16 A11A9 14 15 A10 The 6507 uses a 28 pin configuration with 13 address pins and 8 data pins The seven remaining pins are used for power the CPU timing clock to reset the CPU to request a CPU wait state during its next memory read access the RDY pin and for the CPU to indicate if a read or write memory or MMIO device access is being performed There is no IRQ or NMI pin on the processor The RDY pin is not included on all other 28 pin cut down versions of the 6502 Within the Atari 2600 RDY is used to synchronise the CPU to the television video lines This function is essential for the racing the beam method used by the 6502 and Atari Television Interface Adaptor chip to generate the television video signal 13 In response to a specific address access the TIA will assert RDY to halt the CPU until the end of the current video scan line 14 References Edit The MOS 6502 and the Best Layout Guy in the World swtch com 2011 01 03 Retrieved 2014 08 09 MOnSter6502 monster6502 com 2017 Retrieved 2017 05 01 Bagnall Brian Commodore Variant Press We sold a microprocessor RAM ROM and I O chip all for twelve bucks Bagnall Brian Commodore Variant Press The 6507 which was a subset of the 6502 could be made at a cheaper price It was designed to be a really small package Oral History of Charles Ingerham Chuck Peddle PDF June 12 2014 p 58 Retrieved 2021 05 30 You don t use a 68000 as a logic replacement you use it as a computer And that s a different architecture And we weren t capable of going there without a major investment It s supposed to have been in every cash register it s supposed to have been in every intelligent thing on the airplane it was supposed to be everywhere a href Template Cite web html title Template Cite web cite web a CS1 maint url status link Visual6502 Visual6502 org 6502 vs 6507 When Pac Ruled the Earth Electronic Gaming Monthly No 62 EGM Media LLC September 1994 p 18 Atari 850 Interface Module Field Service Manual Internet Archive 1981 Retrieved 2021 06 03 Block Diagram a href Template Cite web html title Template Cite web cite web a CS1 maint url status link Atari 810 Disk Drive Field Service Manual Internet Archive 1980 Retrieved 2021 06 03 Block Diagrams And Schematics a href Template Cite web html title Template Cite web cite web a CS1 maint url status link Service Manual For The Atari 1050 Disk Drive Internet Archive 1983 Retrieved 2021 06 03 Electronic Theory a href Template Cite web html title Template Cite web cite web a CS1 maint url status link Atari 2600 Specifications Retrieved 2021 05 31 Memory Mirrors a href Template Cite web html title Template Cite web cite web a CS1 maint url status link Peter Turnbull January 25 2005 MOS 6507 Tech Spec s Miner Jay October 22 1976 TIA 1A Television Interface Adaptor Model 1A Internet Archive Archived from the original on 2008 04 24 Retrieved 2021 06 04 This circuit operates on a line by line basis always outputing the same information every television line unless new data is written into it by the microprocessor Wright Steve May Darryl 1988 2600 STELLA Programmer s Guide Internet Archive Retrieved 2021 06 01 Simply writting sic to WSYNC causes the microprocessor to halt until the electron beam reaches the right edge of the screen Further reading EditCommodore Semiconductor Group 6500 Microprocessors Archived 2020 10 01 at the Wayback Machine November 1985 p 11 See also List of books about 65xx microprocessor families Retrieved from https en wikipedia org w index php title MOS Technology 6507 amp oldid 1126768678, wikipedia, wiki, book, books, library,
