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Amiga Technical References

A2386SX Bridgeboard Information

Jumper and socket locations:

| The  -------------        J101   ----- -----                      |
|Bridge|    ZIP    |               |   | |   |                J515  |
|      |    RAM    |               |386| |FPU|                      |--
|      |  Sockets  |               |   | |   |                      | |
|      -------------               ----- -----               J501   |F|
|                                                            J502   |L|
|                                                                   |O|
|                                                                   |P|
|                                                                   |P|
|                                                     J506          |Y|
|                                                                   | |
|                                       J601                        |--
|                                                                   |
|                                                                   |
|                                                                   |
|                                                                   |
|                                                                   |
     |      Zorro Connector      |  |    AT    | |      XT       |
     -----------------------------  ------------ -----------------

Jumper Information.

  • J101: (ON) Enables Pipeline mode. If removed, Pipeline mode is disabled.

  • J501, J502: (1-2) Select the type of internal drive. Pins 1-2 for PC drives, Pins 2-3 for Amiga. Both jumpers must be set the same.

  • J506: (ON) Enabled on-board PC floppy drive access. If removed, the floppy drive controller DMA is disabled.

  • J515: (1-2) Select which Amiga drive is used as the shared drive. Pins 1-2 for DF0, Pins 2-3 for DF1

  • J601: (ON) Enables on board PC floppy drive access.
Default positions in bold. The user should only need to change J501, J502 and J515.

Expansion Issues:

Here are memory locations, I/O ports and interrupts to avoid when adding PC peripherals.

Memory Locations to avoid:

 A0000 to AFFFF: If Janus handler load segment is set to A0000 in PCPrefs.
 B0000 to B1FFF: If Monochrome display adapter emulation is enabled in PCPrefs.
 B8000 to BFFFF: If Color display adapter emulation is enabled in PCPrefs.
 D0000 to DFFFF: If Janus handler load segment is set to D0000 in PCPrefs.

I/O Ports to avoid:

 000-00F            0F0
 0C0-0DE            0F1
 060                0F4
 061                0F5
 062                0F8-0FE
 064                2Fx
 070                37x
 087-08F            3Bx      If MDA emulation is enabled.
 092                3Dx      If CGA emulation is enabled.
 0E8-0EF            3F0-3F7  If on-board floppy access is enabled.

Interrupts to avoid:

 IRQ6  If on-board floppy access is enabled.

Aren't you glad you have AutoConfig!

Technical Specifications:

  • Function: Provides an IBM-PC/AT compatible coprocessor system for a computer in the A2000/3000/4000 series.

  • Processor: 80386SX

  • Clock Speed: 16mhz, 20mhz or 25mhz

  • Coprocessor: Optional 80387SX FPU supported

  • Memory: 1MB supplied (expandable to 8MB)

  • Floppy Disks: Supports up to 2 floppy disk drive from the following:

    1. One PC-only external drive (3.5" or 5.25")

    2. Two PC-only internal drives of same computer type (PC or Amiga), 3.5" 1.44MB PC drive, 3.5" 720KB/880KB PC or Amiga drive, 3.5" 880KB/1.76MB dual-speed Amiga drive, 5.25" high density, or 5.25" low density.

    3. One shared 3.5" Amiga drive

  • Card Type: Uses both Amiga bus and PC ISA bus. Occupies one of the two combined positions.

  • Video Display:

    1. IBM-PC/AT MDA Monochrome 80x25 text mode.

    2. IBM-PC/AT CGA Color text (80x25 & 40x25) and graphics (640x200x2 & 320x200x4 color) modes supported in Amiga windows simultaneously.

  • Keyboard: IBM-PC/XT keyboard emulation using the Amiga keyboard

  • Parallel Port: IBM-PC/AT compatible Centronics port emulation using the Amiga's parallel port.

  • ROM: 64KB AT-compatible BIOS

  • Interprocessor Communications: 128K of shared memory, ability for PC to interrupt Amiga and vice versa.

  • Power: 2.5 amps @ 5.0V

Copyright © 2000 Amiga Auckland Inc. All rights reserved.
Revised: June 16, 2005.