connects to: Other
A3000 with twin floppy drives
A3000 with single floppy drive
Rear of A3000
Left side of A3000
Right side of A3000
RomTower front
Rom tower back
Image inside A3000
- 1250 x 1312, 318K
A3000 Revision 6.1 Motherboard
- 2217 x 2016, 1,218K
A3000 Revision 7.0 Motherboard
- 1959 x 1952, 1,205K
A3000 Revision 9.0 Motherboard
- 1728 x 1704, 569K
A3000 Revision 5.0 Daughterboard
- 2916 x 1012, 1,003K
A3000 ROM Tower
- 1708 x 1452, 632K

Standard Specifications


Case Type: Desktop
Processor: 030@16Mhz or
MMU: Internal
FPU: 68881@16Mhz (for 030@16Mhz version)
68882@25Mhz (for 030@25Mhz version)
Chipset: ECS (Plus additional chips such as Amber, SuperDMAC and Ramsey)
Kickstarts: V1.4 (Special Kickstart versions which boots the real Kickstart from a file called dev:kickstart)
V2.04 (in ROM, or disk based for Kickstart V1.4)
Bus Controller: Fat Buster Rev 2
Super Buster Rev 6
Super Buster Rev 7
Super Buster Rev 9
Super Buster Rev 11 (unconfirmed)
Expansion Slots: 4 x 100pin Zorro III slots
1 x ECS Video Slot (inline with Zorro)
2 x Inactive 16bit ISA slots (inline with Zorro)
1 x 200pin CPU Fast Slot.
Standard CHIP RAM: 1MB
RAM sockets: 44256 DRAM DIP Sockets for Chip RAM (Max 2MB)
ZIP sockets and DIP sockets for fast RAM
Hard Drive Controllers: 1 x SCSI-II controller
Drive Bays: 3 x 3.5" Drivebays (2 with faceplates, these are fixed as part of the A3000 case)
Expansion Ports: 1 x 25pin Serial
1 x 25pin Parallel
1 x 23pin RGB Video
1 x 15pin VGA
1 x 23pin External Floppy
2 x 9pin Joystick/Mouse
2 x RCA Audio (Left/Right)
1 x 25pin SCSI Connector
1 x large 5pin DIN Keyboard connector
Floppy Drive: 1 x Internal 880K Floppy Drive or
1 x Internal 1.76MB Floppy Drive
Motherboard Revisions: Rev 6.0 (pre-production)
Rev 6.1 (First production release)
Rev 7.1 (Used ROM tower)
Rev 7.2
Rev 7.3
Rev 8.0
Rev 8.9
Rev 9.0 (no ROM Tower, jumpers are labelled)
Battery Backed Up Clock: Yes, uses "Barrel" shaped battery.

The A3000 is regarded by some Amiga fans as the best model ever made, but they generally forget about the A3000T and A4000T which actually offer a lot more. The A3000 unlike most Amiga models, supports both ROM based Kickstarts and disk based Kickstarts, although not simultaneously. Kickstart V1.4 is actually a special version of Kickstart which loads the real Kickstart from a file called DEVS:Kickstart. Kickstart V2.04 was available as a ROM, or as a disk based version for use with A3000's which had Kickstart V1.4. A3000's fitted with Kickstart V1.4 cannot use 040 or 060 processors, regardless of what version of Kickstart is eventually booted, because it relies heavily on the integrated MMU in the 030 which varies to some degree from the MMU in 040 and 060 processors. The A3000 also contains a built in scandoubler and flicker fixer so that standard PC type SVGA monitors can be connected and display the native (PAL/NTSC) screen modes. It was available as a separate card for other Amigas called the A2320. The scandoubler can be disabled if necessary by a switch on the back of the machine. There is also a variable switch to finetune the scandoubler. The A3000 has a SCSI-II controller (WDC33C93) on the motherboard which is much faster than the standard IDE Controller that was supplied with the A4000 and other models. However some motherboard revisions have SCSI termination directly on the motherboard and others don't. You may find you need at least one SCSI device attached in order to boot, even from floppy disk. The A3000 is one of the few models of Amigas which actually has some NVRAM, primarily for storing the configuration settings of the SCSI controller, such as Controller ID, SCSI bus timeout, Synchronous mode and LUNs.

There are RAM sockets on the motherboard for expanding CHIP RAM up to 2MB, providing your Agnus chip supports it. These are in the form of DIP sockets. The motherboard also contains 32 ZIP CHIP sockets and 20 DIP sockets for adding additional memory. If the DIP sockets are used then only a maximum of 4MB of Fast RAM can be added. If ZIP memory is used then 16MB of Fast RAM can be added. The ZIP and DIP sockets cannot be used simultaneously. If you intend to use Zorro III cards which make use of Zorro III DMA then you need to upgrade Buster to Rev 11. The Zorro III and ISA expansion slots are on a daughterboard (riser card) which is connected to the motherboard and rises vertically from it.

SCSI Problems

The A3000 may suffer SCSI related problems when several SCSI devices are attached to the bus. The most common are random SCSI bus lockups, especially with CD-ROMs and tape driver and random checksum errors when copying large files between devices. These problems can, in most cases (providing termination and jumpers are correct) be attributed to the WD33C93A SCSI controller chip in the A3000. Most, if not all, A3000s shipped with the WD33C93A-PL 00-04 chip revision. This chip had known bugs when multiple devices were present on the SCSI bus. The WD33C93A-PL 00-08 chip revision addresses and fixes the above problems.

WD33C93A-PL 00-08 9131 F (Latest Revision)
WD33C93A-PL 00-04 9201 D (default release)

INT2 Modifications

Certain accelerators, primarily those with onboard SCSI may require the INT2 modification to function fully. The A3000's CPU Fast Slot does not contain the INT2 signal as found on the A3000T, A4000 and A4000T. An INT2 modification guide can be found here.

Motherboard Layout


  1. RCA Stereo Jacks
  2. VDE selector switch
  3. Video finetune adjustment
  4. VGA connector
  5. Amiga Video connector
  6. SCSI & Parallel port
  7. External Floppy
  8. Serial port
  9. Amber gate array
  10. System expansion bus
  11. Super DMAC gate array DMA controller for SCSI
  12. System ROM
  13. Paula Audio I/O
  14. Denise Enhanced 1280 hires
  15. Fat Agnus
  16. Fat Gary gate array system address decoding
  17. Fast RAM
  18. Chip RAM
  19. Fat Buster gate array DMA Arbitur for motherboard
  20. MC68030 microprocessor 16/25 Mhz
  21. MC68881/82 Math coprocessor
  22. Ramsey gate array Dynamic-static RAM controller
  23. Fast RAM (DIP)
  24. CPU Fast Slot
  25. Mouse/Joystick
  26. Mouse/Joystick
  27. Keyboard
  28. Internal SCSI and Floppy Connectors
  29. System power 135 Watt power supply



25 MHz PAL
J100 4 2-3 2-3 1-2 1-2 QUADCLK (Quadrature Clock Source)
J101 3 2-3 2-3 2-3 2-3 FPU Clock Source
J102 3 2-3 2-3 2-3 2-3 BRDCLK (System Clock Source)
J103 4 3-4 3-4 3-4 3-4 FPU CS/BERR
J104 3 1-2 1-2 1-2 1-2 CPUCLK (CPU Clock Source)
J151 3 2-3 2-3 1-2 1-2 ROM Timing
J152 3 2-3 2-3 1-2 1-2 ROM Timing
J180 3 2-3 2-3 2-3 2-3 A2000 ROM Compatibility Jumpers
J181 3 2-3 2-3 2-3 2-3 A2000 ROM Compatibility Jumpers
J200 3 1-2 2-3 1-2 2-3 NTSC/PAL Select
J350 3 1-2 1-2 1-2 1-2 Tick Clock Source
J351 3 2-3 2-3 2-3 2-3 Disable DF1: (1-2 enable)
J352 2-3 2-3 2-3 2-3 Light Pen Source
J481 3 2-3 2-3 2-3 2-3 VDE Scan Double Only Jumper
J482 3 1-2 1-2 1-2 1-2 VDE PLL Loop Adjust
J483 3 - - - - VDE Factory Test Points
J800 3 1-2 1-2 1-2 1-2 WD33C93
J851 3 1-2 1-2 2-3 2-3 RAM Controller Speed Jumper
J852 5 4-5 4-5 4-5 4-5 -012A Ramsey Only (See Notes)
J852 connecting pins 2 & 3 : 1Mbit, in 256k x 4
J852 connecting pins 1 & 2 : 4Mbit, in 1m x 4
J853 3 2-3 2-3 2-3 2-3 -012A Ramsey Only (See Notes)

J150, J151: ROM Timing.
The ROM timing circuit provides four different speed settings to match the output enable and access timing of the system ROMs. To set the jumpers, determine the output enable time and access times for the ROMs you wish to use. The ROM must have lower values than the setting you select. System standard ROMs have T(oe) = 110ns and T(acc) = 250ns.


CLOCK J151 J150 T(oe)(min) T(acc)(min)
16Mhz 2-3 2-3 157ns 250ns
16Mhz 2-3 1-2 220ns 312ns
16Mhz 1-2 2-3 282ns 375ns
16Mhz 1-2 1-2 345ns 437ns
25Mhz 2-3 2-3 90ns 160ns
25Mhz 2-3 1-2 130ns 200ns
25Mhz 1-2 2-3 170ns 240ns
25Mhz 1-2 1-2 210ns 280ns


  J180 J181
A2000/A500 ROMS 1-2 1-2
A3000 ROMS 2-3 2-3


  J852 J853
-012A Ramsey w/ 256K4 RAMs 4-5 2-3
Later Ramseys w/ 256K4 RAMs 2-3 1-2
Later Ramseys w/ 1M4 RAMs 1-2 1-2