Wikipedia

MOS Technology 6510

(Redirected fromMOS Technology 8501)

"6510" redirects here. For the mobile phone, seeNokia 6510.

TheMOS Technology 6510is an8-bitmicroprocessordesigned byMOS Technology.It is a modified form of the very successful6502.The 6510 is widely used in theCommodore 64(C64)home computerand its variants. It is also used in theSeagate ST-251MFM harddisk.[1]

MOS Technology 6510
General information
Common manufacturer
Performance
Max.CPUclock rate0.985 MHz to 1.023 MHz
Data width8
Address width16
Architecture and classification
Instruction setMOS 6502
Physical specifications
Package
Products, models, variants
Variant
  • MOS 8500, 7501/8501, 8502, 6510T
History
PredecessorMOS 6502
SuccessorMOS 8502
Image of the internals of a Commodore 64 showing the 6510 CPU (40-pin DIP, lower left). The chip on the right is the6581 SID.The production week/year (WWYY) of each chip is given below its name.

The primary change from the 6502 is the addition of an 8-bit general purposeI/Oport, although 6 I/O pins are available in the most common version of the 6510. In addition, the address bus can be madetristateand the CPU can be halted cleanly.

Use

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In the C64, the extra I/O pins of the processor are used to control the computer'smemory mapbybank switching,and for controlling three of the four signal lines of theDatasettetape recorder (the electric motor control, key-press sensing and write data lines; the read data line went to another I/O chip). It is possible, by writing the correctbit patternto the processor at address $01, to completely expose almost the full 64KBofRAMin the C64, leaving noROMorI/Ohardware exposed except for the processor I/O port itself and its data directional register at address $00.[2]

Variants

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Pin configuration of the most common variation of the 6510 CPU (/HALT in this image refers to the RDY pin.)

MOS 8500

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In 1985, MOS produced the8500,anHMOSversion of the 6510. Other than the process modification, it is virtually identical to theNMOSversion of the 6510. The 8500 was originally designed for use in the modernised C64, the C64C. However, in 1985, limited quantities of 8500s were found on older NMOS-based C64s. It finally made its official debut in 1987, appearing in a motherboard using the new 85xx HMOS chipset.

MOS 7501/8501

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MOS 8501 CPU

The7501/8501variant of the 6510 was introduced in 1984.[3]Compared to the 6510, this variant extends the number of I/O port pins from 6 to 8, but omits the pins for non-maskable interrupt and clock output.[4]It is used in Commodore'sC16,C116andPlus/4home computers, where its I/O port controls not only theDatasettebut also theCBM Businterface. The main difference between 7501 and 8501 CPUs is that they were manufactured with slightly different processes: 7501 was manufactured withHMOS-1and 8501 with HMOS-2.[3]

MOS 8502

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Main article:MOS Technology 8502

The 2MHz-capable8502variant is used in theCommodore 128.All these CPUs areopcodecompatible (includingundocumented opcodes).[5]

MOS 6510T

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TheCommodore 1551disk drive (for theCommodore Plus/4) uses the6510T,a version of the 6510 with eight I/O lines. TheNMIand RDY signals are not available.

See also

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References

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  1. ^ST-251 schematic
  2. ^Butterfield, Jim (January 1983)."Commodore 64 Architecture".Compute!.No. 32. p. 208.
  3. ^abHardware – MOS 7501/8501
  4. ^CPU 7501 / 8501
  5. ^Graham."6502/6510/8500/8502 Opcodes".oxyron.de.

Further reading

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See also:List of books about 65xx microprocessor families
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Retrieved from "https://en.wikipedia.org/w/index.php?title=MOS_Technology_6510&oldid=1240859211#8501"