Commodore Amiga 1000 - main board - MOS 8367R0-7824

The MOS Technology "Agnus", usually called Agnus, is an

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

in the custom

chipset In a computer system, a chipset is a set of electronic components on one or more integrated circuits that manages the data flow between the processor, memory and peripherals. The chipset is usually found on the motherboard of computers. Chips ...

of the

Amiga Amiga is a family of personal computers produced by Commodore International, Commodore from 1985 until the company's bankruptcy in 1994, with production by others afterward. The original model is one of a number of mid-1980s computers with 16-b ...

computer. The Agnus, Denise and Paula chips collectively formed the OCS and ECS chipsets. The Agnus is the Address Generator Chip. Its main function, in chip area, is the RAM Address Generator and Register Address Encoder which handles all DMA addresses. The 8361 Agnus is made up of approximately 21000

transistor A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electric power, power. It is one of the basic building blocks of modern electronics. It is composed of semicondu ...

s and contains DMA Channel Controllers. The Blitter and

Copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

are also contained here. Originally Agnus was fabricated in 5 μm manufacturing process like all OCS chipset. Agnus features: * Memory controller ("Chip" memory that can be accessed by the processor and the chipset) * The Blitter, a

bitmap In computing, a bitmap (also called raster) graphic is an image formed from rows of different colored pixels. A GIF is an example of a graphics image file that uses a bitmap. As a noun, the term "bitmap" is very often used to refer to a partic ...

manipulator. The Blitter is capable of copying blocks of display data, or any arbitrary data in the chip memory, at high speed with various raster operations as well as drawing pixel perfect lines and filling outlined polygons, while freeing the CPU for concurrent tasks. * "

", a display synchronized co-processor * 25

Direct Memory Access Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system computer memory, memory independently of the central processing unit (CPU). Without DMA, when the CPU is using programmed i ...

(DMA) channels, allowing graphics, sound and I/O to be used with minimal CPU intervention *

DRAM Dram, DRAM, or drams may refer to: Technology and engineering * Dram (unit), a unit of mass and volume, and an informal name for a small amount of liquor, especially whisky or whiskey * Dynamic random-access memory, a type of electronic semicondu ...

refresh controller * Generates the system clock from the 28 MHz oscillator * Video timing Agnus was replaced by

Alice Alice may refer to: * Alice (name), most often a feminine given name, but also used as a surname Literature * Alice (''Alice's Adventures in Wonderland''), a character in books by Lewis Carroll * ''Alice'' series, children's and teen books by ...

in the Amiga 4000 and Amiga 1200 when the AGA chipset was introduced in 1992.

Chips by capability

* OCS Agnus which can address up to 512 KB of Chip RAM (PLCC versions add 512 KB of pseudo-fast RAM) ** 8361 ( DIP) - Amiga 1000 (NTSC); Amiga 2000 model A (NTSC) ** 8367 (DIP) - Amiga 1000 (PAL); Amiga 2000 model A (PAL) ** 8370 ( PLCC) -

Amiga 500 The Amiga 500, also known as the A500, was the first popular version of the Amiga home computer, "redefining the home computer market and making so-called luxury features such as multitasking and colour a standard long before Microsoft or Apple ...

to Rev 5.x (NTSC); Amiga 2000 model B to Rev 4.5 (NTSC) ** 8371 ( PLCC) -

to Rev 5.x (PAL); Amiga 2000 model B to Rev 4.5 (PAL) * ECS Agnus which can address up to 1 MB of Chip RAM ** 8372 - no data* ** 8372A -

from Rev 6 (NTSC/PAL); Amiga 2000 model B from Rev 6.0 to Rev 6.3 (NTSC/PAL); Commodore CDTV ** 8375 (318069-16 only) (PAL) -

from Rev 6 (PAL); Amiga 2000 model B from Rev 6.4 (PAL) ** 8375 (318069-17 only) (NTSC) -

from Rev 6 (NTSC); Amiga 2000 model B from Rev 6.4 (NTSC) * ECS Agnus which can address up to 2 MB of Chip RAM ** 8372AB - Amiga 3000 from Rev 6.1 to Rev 8.9 (NTSC/PAL) ** 8372B - Amiga 3000 Rev 9 (NTSC/PAL) ** 8375 (PAL) -

Amiga 500 Plus The Amiga 500, also known as the A500, was the first popular version of the Amiga home computer, "redefining the home computer market and making so-called luxury features such as multitasking and colour a standard long before Microsoft or Apple ...

; Amiga 600 (PAL) ** 8375 (NTSC) - Amiga 600 (NTSC) * Somewhere 8372A Agnus mentioned as simply "8372".

Chips by package

* 48-lead DIP Agnus (aka thin Agnus): 8361; 8367 * 84-contact PLCC Fat Agnus (named Fat Lady on most Amiga 2000 motherboards) 8370; 8371; 8372; 8372A; 8372AB; 8372B; 8375 Notes
Fat Agnus 1MB and Fat Agnus 2MB also known as Super Agnus; Super Fat Agnus; Fatter Agnus; Big Agnus; Big Fat Agnus.

DMA Channels

Pinout

PLCC versions

When replacing or upgrading chips, pinouts need to be taken care of. Types are just mentioned for reference; four-digit types and pinouts/usage are ''not'' consistent. References: A500 Service Training, A3000 Service Manual, A500+ Service Manual, A1200 schematics

References

;Sources * AMIGA 1000 ASSEMBLY LEVEL REPAIR (Commodore-Amiga, Inc.) 1985 PN 314038-0
Dave's Amiga Schematics and Manuals
* Commodore Amiga A500/A2000 Technical Reference Manual (Commodore-Amiga, Inc.) 198

* A500 SYSTEM SCHEMATICS COMPONENT PART LIST (Rev 6A/7

* A3000 SYSTEM SCHEMATICS (Commodore Business Machines, Inc.) March, 1990 PN-314677-0
www.1000bit.net
* CDTV SERVICE MANUAL (Commodore International Spare GmbH) May, 1991 PN-400403-0
www.ianstedman.co.uk (ZIP-file)
* A500 PLUS SERVICE MANUAL (Commodore International Spare GmbH) October, 1991 PN-400420-0
www.1000bit.net
* A600 SYSTEM SCHEMATICS (Commodore International Spare GmbH) April, 1992 PN-400422-0
www.1000bit.net

OBLIGEMENT: les chipsets de l'Amiga

Big Book of Amiga Hardware
* alexh o

(Agnus 8372B info) * National Amiga Inc.''
mirrored on l8r.net

Marketed Commodore Amiga models

;Notes {{DEFAULTSORT:Mos Technology Agnus MOS Technology integrated circuits Amiga