Sardis Technologies ST-2900 SCSI Hard Disk Drive Adapter

The ST-2900 SCSI Hard Disk Drive Adapter is an expansion board that plugs into the ST-2900 FDC board to provide a SCSI interface to an external hard disk drive.

SCSI Adapter features:

When I discovered the Logic Devices L5380 SCSI host controller chip (similar to the NCR 5380, but better), I decided to see if it could be added to the ST-2900. I designed the supporting circuitry, documented the connections, and wrote an instruction sheet. I even created a PCB layout for it (using the Wintek SmARTWORK PCB CAD software on a friend's computer), then had a single-sided prototype PCB made. But I never assembled the board, and later sold the bare board to a customer, as-is. (From the date on a letter I sent to him that mentioned this adapter, it appears I designed the SCSI interface before the end of August 1988, probably before I designed the SASI adapter for the FDC board.)

By this time sales of the ST-2900 had dwindled, and I was now busy with the DMC software and documentation, so I never put the SCSI adapter into production. And I never wrote any drivers (FLEX or OS-9) for it.

I don't remember why I built the SASI interface instead of this SCSI interface, but it might have been due to the difficulty and expense of obtaining the L5380, whereas the SASI interface used inexpensive common parts?

The person who bought this board can't find the schematics or component layout diagrams for the board, and I haven't found my copy yet, either.

(Click on a picture for a larger version.)
Pictures of partially assembled board (190-197KB .jpg).

ST-2900 SCSI Hard Disk Drive Adapter Build Instructions.
(5KB .txt)
Logic Devices L5380 Data Sheet.
(270KB .pdf)

"FLEX" was a trademark of Technical System Consultants (TSC).
"OS-9" is a registered trademark of Microware LP.

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Last revised 2020-Apr-14 12:37 PDT.
Copyright 2020 by David C. Wiens.

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