A2286 Specifications

Card Type: Uses both Amiga bus (100 pin) and IBM-PC/XT bus system of the Amiga A2000 (goes into combined position).
Function: Provides an 80286 co-processor system with IBM-PC/AT compatibility. Uses AutoConfig features of the Amiga. Socket for 80287 math co-processor.

DATA - 80286 SIDE

Clock Speed: 8 MHz
Memory: 1024 kByte RAM
ROM: 16 kByte BIOS
Interfaces: 1 internal floppy disk drive 5.25" 1.2 Mbyte capacity
1 internal floppy disk drive 3.5" 720 Kbyte capacity (optional)
Parallel Port ( Centronics, IBM-PC compatible emulated on Amiga parallel port).
Slots: 1 IBM-PC/AT / 2 IBM-PC compatible full size slots
Keyboard: AT keyboard emulated on the Amiga keyboard
Video Display: IBM-PC monochrome text mode and color mode are emulated in seperat AmigaDOS windows simultaneously.
System Software: MS-DOS

DATA — AMIGA SIDE

Inter-System Communication: 64 kByte dual-port RAM as inter-process buffer
64 kByte dual-port scratch memory on Amiga side
interrupt logic
Janus emulation software

BUS INTERFACE

Type: Fast dual-port memory, full speed CPU access during system DMA
Card Size: Full size Amiga 2000 card
Power: Supplied by system
Included Items: Janus emulation software on 3.5" floppy disk
Internal floppy disk drive 5.25", 1.2 Mbyte capacity

AT-Emulator ( Main )

a2286_main

AT-Emulator ( Baby)

a2286_baby

Jumper

J2 speaker (signal with 33R serial resistor)
Position: main board
J4 enable/disable onboard FDC
Position: main board
  onboard FDC enabled onboard FDC disabled
J5 enable/disable 384K above memory
Position: baby board
  above memory enabled above memory disabled
J6 floppy disk select
Position: baby board
  PS / 2 type 1.44 Mbyte AT type 1.2/1.44 Mbyted
J7 test connector
Position: main board
  1: NC 2: NC 3: KBDATA 4: KBCLK
5: PWRGOOD 6: KEY 7: +5V 8: GND
J13 battery connector for RTC
Position: main board
J14 video startup mode select
Position: baby board
 

MDA Monochrome 80x25 text mode

CGA Color text (80x25 & 40x25) and graphics (640x200x2 & 320x200x4 color)

Solder Jumper

JS1A / JS1B DMA speed select
Position: main board
JSlA closed,
JS1B open		 DMA works at sysclock/2 speed (default)
JSlB closed,
JS1A open		 Dma works at sysclock speed
JS2A / JS2B RAS to CAS signal delay select
Position: baby board
JS2A closed,
JS2B open		 RAS to CAS delay is 50 ns (default)
JS2B closed,
JS2A open		 RAS to CAS delay is 75 ns
JS4A / JS4B Onboard or external l6MHz Oscillator select
Position: baby board
JS4A closed,
JS4B open		 selects 16 MHz for FDC from main PCD (default)
JS4B closed,
JS4A open		 selects 16 MHz from U69
(JS4B should only be closed, if oscillator U69 is stuffed)
JS5A / JS5B BIOS EPROM type select
Position: baby board
JS5A closed,
JS5B open		 27128 EPROM (default)
JS5B closed,
JS5A open		 27256 EPROM
JS7A / JS7B / JS7C / JS7D APU 80287 speed select
Position: main board
JS7B / JS7D closed,
JS7A / JS7C open		 APU runs at sysclk speed (default)
JS7B / JS7D open,
JS7A / JS7C closed		 APU runs at sysclk/2 speed
JS8A / JS8B real time clock bus timing select
Position: baby board
JS8A closed,
JS8B open		 80286 timing (default)
JS8B closed,
JS8A open		 27256 MOTOROLA timing
JS9 real time clock standby mode
Position: baby board
JS9 closed standby mode (default)
JS9 must be closed
JSl0A / JS10B real time clock bus timing select
Position: baby board
JSl0A closed,
JSl0B open		 selects FE 3000 A (default)
JSl0B closed,
JSl0A open		 selects FE 3000 (8MHz version)
JS11 FDC write precompensation select
Position: baby board
JS11 open selects 125 ns (default)
JS11 closed selects 187 ns
JS12 FE 3000 / FE 3000 A select switch
Position: main board
JS12 open selects FE 3000 A (10MHz version) (default)
JS12 closed selects FE 3000

Last Update: 17.07.2023