ZuluSCSI

The ZuluSCSI is a family of SD based emulators designed for narrow and ultrawide low-voltage differential SCSI buses. They aim to provide low-power, higher reliability alternatives to aging SCSI drives in consumer and workstation hardware

Architecture

The ZuluSCSI ffirmware looks for file names which adhere to a simple but powerful naming convention, and presents them as the drives to the SCSI host. Each image file represents a SCSI drive.

ZuluSCSI is designed to power itself solely from SCSI termination power, with no separate power source needed, when the host device/computer provides SCSI termination power. All SGI computers do, as well as the vast majority of other desktop systems with SCSI interfaces.

The ZuluSCSI RP2040 can deliver up to 9.5 megabytes/second, and maximum write speeds of approximately 6 megabytes/second. Throughput rates can be affected by particularly slow (eg. 8MHz 68000) CPUs. SCSI controllers can be, and often are, bottlenecks. Since ZuluSCSI uses the same SCSI command handling code as SCSI2SD V6, compatibility with nearly all devices that speak both SCSI-1 and SCSI-2 is extremely high.

Termination is DIP-switch controlled, and firmware updates are as simple as placing a file on a FAT32 or exFAT-formatted SD card, inserting it in the SD card slot, and applying power to the ZuluSCSI. A firmware recovery mechanism is also provided, as a back-up.

Relevance

The Indy in particular is heat sensitive and relies heavily on passive cooling. This is a better way to maintain low heat output.