ZuluSCSI™ is a SCSI computer storage emulation platform, which speaks both SCSI-1 and SCSI-2. It uses file-based SCSI HDD & CD-ROM images, similar to RaSCSI and BlueSCSI. It represents a fusion of firmware and concepts from both SCSI2SD V6 and BlueSCSI. Hard drive and CD-ROM drive images are stored on a standard FAT32 or exFAT-formatted SD card.
Features
- Open-source firmware, licensed under the GPLv3
- Emulates up to 7 SCSI devices simultaneously, including CD-ROM, Magneto Optical, removable (SyQuest/Jaz-style), and SCSI floppy device types
- Speaks both SCSI-1 and SCSI-2, including 10MB/sec Fast SCSI
- Up to 9.5 megabytes/second read speeds, 6MB/sec write speeds (on ZuluSCSI RP2040-based models)
- SCSI Termination is DIP-switch controlled
- Firmware upgrade simplicity; As easy as placing a file on the SD card
- Highly configurable using a text-based ini file, ZuluSCSI.ini
- External activity LED pin header for attaching remote activity LED
- Designed to be powered via SCSI termination power, when provided by the host
- Optional DB25 pin header for direct installation of an external SCSI connector, in addition to the Single-Ended 50 pin IDC connector
- Identical dimensions and mounting holes as that of SCSI2SD V5.1, V5.2, and V6, making it compatible with many existing SCSI2SD-specific mounting solutions
- SCSI bus transceivers, as used in SCSI2SD V5 and SCSI2SD V6 Rev F
Firmware structure
- SCSI command implementations are from SCSI2SD
- SCSI physical layer code is mostly custom, with some inspiration from BlueSCSI
- Image file access is derived from BlueSCSI
Major improvements from BlueSCSI and SCSI2SD
- Separation of platform-specific functionality to separate directory to ease porting
- Ported to the RP2040 and GigaDevice GD32F205 ARM Cortex processors
- Removal of Arduino core dependency
- Simultaneous transfer between SD card and SCSI bus for improved performance
Origins and License
Firmware origins
The ZuluSCSI™ firmware is derived from two sources, both under GPL 3 license:
- SCSI2SD V6
- BlueSCSI, which in turn is derived from ArdSCSIno-stm32.
Hardware
The ZuluSCSI™ RP2040, V1.0 and V1.1 hardware designs are derived from the SCSI2SD V5.1 hardware design. The ZuluSCSI™ RP2040 Mini hardware designs are derived from the SCSI2SD V5.5 hardware design.