The GVP A1291 is a SCSI module designed for use with the GVP A1230+ JAWS-II accelerator. It offers an external DB25 SCSI connector.  It supports Sync SCSI communications when configured and used with devices that are capable of Sync negotiation.  The FastPrep 2.51 and GVPSCSICtrl support tools provide the means to configure and enable the best performance.

The driver for this product is gvpscsi.device v5.x, with the latest SCSI interface image available on the support website along with disk images available for download and further documentation.  These v5 tools are not interchangable with the v3.x/4.x gvpscsi.device tools from the Series II products, nor is it compatible with the GuruROM V6 3rd-party upgrade product.

A software-loaded update to the SCSI device driver (via Binddrivers and the driver+icon being placed in SYS:Expansion) was made available after the prduct release.  It will not be possible to AutoBoot from the SCSI interface with the updated driver, but it may support some specific/additional removable media/optical devices.  It is generaly not required. 

Additional control of the SCSI interface can be done with the GVPSCSICtrl tool.  Available options, most as icon tool-types, include POLL=ON|OFF, UNIT=#|ALL, DISCONNECT=ON|OFF, MOUNT, RESCAN, FULL, QUIET, BUSHOLD=#, UNLOCK, SYNCHRONOUS=ON|OFF, HIGHSPEED=ON|OFF

Previously little-documented but possibly useful commands:
- Unlock - to unlock a removable media device.  Beware of open files on the target device before using this.  ToolType Ex: UNLOCK UNIT=2
- Synchronous - may improve performance if the target device supports it.  ToolType Ex: UNIT=1 SYNCHRONOUS=ON
- Highspeed - may imrprove SCSI performance on some faster SCSI devices, is slightly out of spec for data reads but not writes.  ToolType Ex: HIGHSPEED=ON
- Bushold - This option will modify the bus 'hold' time of the DMA controller.  Internal default is a value of 3.  It could be useful to adjust in cases where longer/shorter SCSI DMA bus hold activity is desired at the likely expense of CPU memory access performance during I/O activity.  ToolType Ex: BUSHOLD=n UNIT=2 (where n=0-14, default = 3). 

BOM details from internal GVP documents can be found here:

Page contributors: NicDouille, Robert Miranda (GVP Tech Support)
Updated: 5/7/2022 . Added: 12/22/2004