SCSI2SD old

A device that presents a USB Mass Storage device as a Direct Access device to a SCSI controller.

Why ?

Because there are many vintage computers out there that require a 50-pin SCSI drive to boot from. Such disks are only available second-hand, and it's getting harder and harder to find a working disk.

The price of commercial SCSI converters can be much higher than the vintage computers they are used in. However, these devices are still readily available. See :

• http://www.pc-pitstop.com/scsi_ide_adapters/

Why USB ?

Because USB Mass Storage devices already understand SCSI commands.

Parts Required

• SCSI Terminator. TI UC5601DWPG4
• AT90USB1286
• 50 pin IDC header
• USB socket
• 5V supply via Molex drive connector
• (Check) 3.3v to 5v level converter ?
• TI CD74AC280E/74HC280 Parity checker/generator.

Links

The following projects will be of great help:

• AVR based SCSI RAM disk (Open-source AVR microcontroller SCSI interface)
• LUFA Open-source AVR microcontroller USB stack.
• SCSI parity generator

Reference information:

• Interface Circuits for SCSI Design Notes