Big Book of Amiga Hardware

The GVP Series II HD8+ and HD+ (*) is a high performance SCSI controller and memory expansion for the A500/+.  It connects to the left side expansion slot of the A500/+, and closely matched the case aesthetics. The unit has 4x 30-pin SIMM sockets that can utilize up to four 1Mx8 or two 4Mx8 SIMM modules. A power supply for the GVP unit is required unless an A500 PSU with upgraded 5v/12v ratings is used and modifications to the PCB pads are made.  This unit uses standard 30-pin SIMMs, and does not use the GVP SIMM32 modules.  Early units may have had labels with 'Impact' on them, but all will have Series II in the name.  The [GVP A530] is a different product, with a 68030 processor, and uses different RAM.

(*) The products are identical/same internals although the product label changed at some point.  They all had Series II identification.  Early models had the old 'Impact' marketing name.

• 2/4/8MB, zero-wait state, FastRAM controller and ANSI XT3T9.2 compatible SCSI interface.
• GVP Dual Port RAM Controller w/High performance DMA transfers to and from hard-disk.
• SCSI raw data transfer rates of up to 3.58MB/sec.
• Auto-configuration for both Fast RAM and SCSI interface.
• Internal 50-pin SCSI connector, External 25-pin SCSI connector (DB25).
• Internal expansion slot for an 80286-based PC emulator card
• FastROM 3.x/4.x, can be disabled with switch for game compatibility. 
• Compatible with GuruROM v6.

Power Connector Pinout:

Looking at the back of the unit:

   1     3
    4   5
      2

1  Earth Ground
2  Signal Ground (5V ground)
3  +5V RED
4  WHITE (not connected)
5  +12V BROWN