Amiga Storage Peripherals


Commodore A2090

> Company: Commodore, USA
Date: 1987
Amiga: 2000, 3000, 4000
Interface: Zorro 2
Autoconfig ID: 514/1, 514/3

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
cannot autoboot
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)

Images

Amiga Commodore A2090

Front: Amiga Commodore A2090