For fans of vintage computers from the 80s and 90s, SCSI can be a real pain in the neck. The stock of working hard drives is dwindling, and mysterious termination issues will have you cursing SCSI voodoo before long. Over the years, this has led to various projects to create new SCSI hardware to replace original equipment too broken to use or too rare to find.
[David Kuder]it’s small SCSI emulator is designed solely for this purpose. [David] combined a Teensy 3.5 with an NCR5380 SCSI interface chip to build his device. With a 120 MHz clock and 192 KB of RAM, the Teensy provides plenty of power to keep up with SCSI signals, and its DMA features don’t hurt either.
Today, many earlier SCSI emulation or conversion projects focused solely on storage, such as the SCSI2SDwhich emulates a SCSI hard drive using a microSD card for storage. [David]managed that, maximizing the throughput of the NCR5380 with plenty to spare on the SD card. Future work is looking to gain more speed through an upgrade to the SCSI controller.
But that’s not the only reason SCSI is good. Back in the wild days of the 80s, many computers, and especially the front-line Macintosh, lacked expansion options. This led to the development of Ethernet SCSI adapters, which [David] also trying to emulate by adding a W5100 ethernet shield to his project. So far the Cabletron EA412 driver [David] uses causes the Macintosh SE test system to hang after initial setup, but debugging continues.
It’s always great to see projects that aim to keep vintage hardware alive, like this mass repair of six Commodore 64s.
