I am not absolutely sure just how many variants there were of the
A2000, but the decision to design the system with an open architecture
certainly extended it's life expectancy. Commodore constantly provided
upgrades for the machine, not just at base level but also to the
cards used within it.
The original A2000 was shipped only with a single floppy drive, but
was soon upgraded with an A2090 SCSI hard drive controller and so
was born the Amiga 2000/HD. The A2090 was then upgraded to the
A2090A and shipped with an upgrade kit called the A2094. Not sure
why there had to be another number version, though Commodore
referencing is an art in itself.
The A2000/HD shown in these images was obtained from Germany and
has the A2090A card inside that did drive a Quantum hard drive
with 1.3 autobooting WB. Sadly the drive kicked the bucket a year
or so ago though there are the very tiniest glimmers of life from
the drive when the machine boots. So I haven't given up all hope.
Was just 40MB and had but the 1.3 on the drive so no hardship.
A further card was issued in the early nineties badged the A2091,
though this card had the drive on the card itself.
This mostly from the Amiga Hardware Database:
The card is a SCSI and ST-506 controller and supports up to seven
SCSI and two ST-506 devices. The SCSI drives are controlled by a
WD 33C93 IC with the ST-506 drives controlled by the Zilog Z80B.
The card has a 33C93 chip which 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.
There are three autoboot ROMs. It has custom bootblock design though
does not support the SCSI Direct protocol. The card cannot support
drive partitions and drives larger than 256 MB. Also the ST-506
interface does not support 16-head drives.
Card is fitted with a 50 pin internal SCSI connector and DB25 external
connector. It has a hard disk activity LED connector. Note that
on the Zorro III machines the card only works if the driver and
all the buffers are loaded into chip RAM
The card has an A-Max II driver (hddisk.amhd)
The Amiga 2094 Hard Disk Kit: Includes:
The Amiga 2090A autoboot ST506/SCSI hard disk controller card.
One 3.5" hard disk drive with 40 MB capacity.
Four machine screws, four stand off and four washers used to mount
the hard disks to the chassis.
Two ribbon cables - 34 pin connector and 20 pin connector.
The Kickstart ROM version 1.3.
The Reinstall disk.
The Workbench 1.3 and Extras 1.3 disks.
The AmigaDOS 1.3 Enhancer manual.
The A2090 User's Guide with additional information on the A2090A.
The A2000 HD works a treat and I removed the battery a good while
back. Sadly the hard drive is not working. No biggy.