This is the original GVP Impact (Series I) disk controller technology upgraded with an optional 2MB of 16-bit FastRAM expansion. It is based upon a 33C93/33C93A 8-bit SCSI controller that can transfer data to/from an onboard 16K SRAM buffer, which is then serviced by the CPU. The board has space to mount a 3.5" hard disk with a short 2-3" internal cable, and an external DB25 interface. SCSI bus termination resistor packs are soldered in. It supports 2x standard 30-Pin SIMM memory of 80ns or better for memory expansion.
GVP 1.0, 2.0, and FastROM 3.x is supported for Autoboot. U42/4711 must be on the board to support the FastROM v3.x single-ROM in U30, or the double-ROM version must be obtained from the driver writer's website (see the GVP HC8 page for the link).
There are documented jumpers for Autoboot (ROM) disable (J4 removed), and RAM Enable/Disable (J2 off=enable). All others jumpers are reserved. They include test jumpers for J5 - disable the SRAM buffer, and J3 - AutoConfig disable. U50 and J6/7/8 were intended as software-readable options, but were never implemented. There is no HDD LED on the card - use the option on the mounted hard disk or connected device if available.
All capacitors on the board are for RF noise suppression and related FCC purposes, and do not otherwise affect board operation.