This is the original GVP Impact (Series I) disk controller technology. It is based upon a 33C93/33C93A 8-bit SCSI controller which transfers data to/from an on board 16K SRAM buffer (4K on the original SCSI+RAM 1/0 revision from which it came from), which is then serviced by the CPU. The board has space to mount a 3.5" hard disk with a short 2-3" internal 50-pin ribbon cable. SCSI bus termination resistor packs are soldered in. Early controllers have a diode for SCSI bus power that may burn out if a device also supplies power. Ribbon cables have also burned that line in some cases. The diode was left out in later builds to prevent this. Typical SCSI disk drives shipped on the card included Quantum 40S/80S, Seagate 20M, 30M, 45M, and Miniscribe 20MB. GVP 1.0, 2.x, and FastROM 3.x is supported for AutoBoot. Related models in this line supporting RAM include the GVP Impact HC+2, and the non-hardcard GVP Impact SCSI+RAM products (1/x, 2/x, 8/x) with various RAM configurations combined with a 33C93/33C93A 8-bit SCSI controller.
Connectors
| Connector |
Function |
| CN1 |
LED Connector |
| U3 |
Autoboot EEPROM |
| J4 |
Auto Booting |
| CN2 |
50pin SCSI Connector |
Note: Most boards shiped with a 33C93 SCSI chip. Use of the 33C93A SCSI chip (as a replacement) will be detected by FastROM 3.14/3.15 and expect 14MHz clocking of that chip which is not possible on Series I cards except the SCSI+RAM 8/x. Use a v3.12 FastROM (gvpscsi.device) in this case for booting, or boot from another device (without the ROM active), place the GVPSCSI driver in the SYS:Expansion drawer, and make sure the driver's icon tooltype indicates 7MHz.
AutoConfig Notes:
- Rev 3 - 2017/3
- Rev 4 - TBD
- Rev 5 - TBD
Note: 2017/2 has been reported, but not verified.
The Rev 3 128K PIC card has been tested functional outisde of the common $E90000-$EFFFFF Z2 I/O AutoConfig space.
Notable PCB revisions:
Rev 3 - Inital Release . Original PALs U2/6089 & U18/61CD have an AutoConfig flaw which exposed more than 64K of the PIC while waiting at $E80000 for AutoConfig. If the card was not the first I/O PIC, OS activity against a PIC already programmed to $E90000 could collide with the card. Updated PALs are U2/6D7B & U18/6215. U1/536D remained unchanged.
Rev 4 - Updated PALs from Rev 3 transferred to Rev 4.
Rev 5 - AutoConfig size dropped to 64K, Has an updated U1/537B and U18/7667. U2/6D7B remained unchanged. D1 diode was removed from production due to back-feed on the TrmPwr line from external devices which a) already provided it, and b) may have used a different PSU technology than the Amiga's or was unregulated. The result of a backfeed was a burned-out diode and/or a burned trace/wire in the cable from overheating.
The Rev 3/4 boards are darker green, and may have some wider foil-like traces evident. They occasionally may have an extra soldered-on ceramic cap on the rear of the PCB
The Rev 5 used more modern PCB manufacturing and may have appeared a more yellow/golden .
All boards came with soldered-on 3-4 inch HD power pigtails.