This is the original GVP Impact (Series I) disk controller technology.  It is based upon a 33C93/33C93A 8-bit SCSI controller that can transfer data to/from an on board 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.  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, 2.0, 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 with various RAM configurations combined with a 33C93/33C93A 8-bit SCSI controller.



Connector Function
CN1 LED Connector
U3 Autoboot EEPROM
J4 Auto Booting
CN2 50pin SCSI Connector



Page contributors: Gordon Cunningham, Mario Misic, Robert Miranda (GVP Tech Support)
Updated: 10/4/2016 . Added: 12/22/2004