A2090A

A2909A

Company

Commodore, USA

Date

1988

Amiga

A2000, A3000, A4000

Interface

Zorro II

Autoconfig ID

514 / 1
515 / 3

SCSI and ST-506 controller

  • supports seven SCSI and two ST-506 devices at once
  • the SCSI drives are controlled by the WD 33C93 IC
  • the ST-506 drives are controlled by the Zilog Z80B CPU
  • the 33C93 chip can be controlled by either the 68000 (default) or by the Z80
  • DMA transfers are provided by the custom Commodore 8727 IC featuring a 64 byte FIFO buffer
  • the Z80 CPU has 2 kB RAM to buffer commands from the Amiga, 8 kB PROM with driver routines and 1 kB RAM for storage of variables
  • three autoboot ROMs
  • custom bootblock design
  • does not support the SCSI Direct protocol
  • does not support partitions and drives larger than 256 MB
  • the ST-506 interface does not support 16-head drives
  • 50 pin internal SCSI connector
  • DB25 external connector
  • hard disk activity LED connector
  • on Zorro III machines the card only works if the driver and all the buffers are loaded into chip RAM
  • A-Max II driver (hddisk.amhd)

hard disk kits

  • the A2090A was sold in kit form which included the controller itself, a hard disk, cables, installation disk and manual
  • A2092: A2090A bundled with a 20 MB Miniscribe 8425 hard disk
  • A2094: A2090A bundled with a 45 MB Toshiba MK-134FA or a 46 MB Rodime RO-3055 hard disk
  • all of these hard disks are ST-506 drives

text source: http://amiga.resource.cx/

installed in: A2500