A2386 Specifications

Technical Specifications:

Function: Provides an IBM-PC/AT compatible coprocessor system for a computer in the A2000, A3000 and A4000 series.
Processor: 80386SX
Clock Speed: 16MHz, 20MHz or 25MHz
Coprocessor: Optional 80387SX FPU supported
Memory: 1MB supplied (expandable to 8MB) (possible A2386SX Memory Configurations)
Memory type: uses 1MB x 4 or 256K x 4 ZIP chips. Recommended speeds are 80ns or faster for 20MHz or 25MHz models, 100ns or faster for 16MHz models
Floppy Disks: Supports up to 2 floppy disk drive from the following:
1. One PC-only external drive (3.5" or 5.25") using Amiga compatible external floppy port.
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 (except in A4000T - see Common Problems)
Card Type: Uses both Amiga bus and PC ISA bus.
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 (A2386SX Bridgeboard Setup)
Interprocessor Communications: 128K of shared memory, ability for PC to interrupt Amiga and vice versa.
Power: 2.5 amps @ 5.0V


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 parentheses. 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:

ports ports comment
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.

Link to the Interrupts

Text based on BBFAQ © Sébastien Boisvert
Last Update: 20.07.2023