Note: Due to semiconductor shortage, stock is limited.

Add a reliable, bootable hard drive solution to computers with SCSI.
This is a super-miniature clone of the SCSI2SD v4.2b by Michael McMaster. Should work with most SCSI hosts, but I designed it with intention of using with classic Macs, and a Mac Plus is what I test them on.

For classic Macs with a DB-25 SCSI port (starting with the Macintosh Plus), just plug this onto the back with a prepared microSD inserted, and you're done!

It has active termination which is always on. If using with other SCSI devices daisy-chained, this device should be at the end of the chain.

Can be powered via SCSI Termination Power or via USB-C.

Note: A stock Macintosh Plus is missing a diode on the motherboard that provides SCSI Termination Power to the DB-25 SCSI port.
It should be a 1A power diode such as 1N400x. I can include this diode with your purchase.
It should be soldered into the empty location next the the SCSI port on the logic board - you can't miss it.
If you don't install this diode, then you need to power the FlashSCSI from a phone charger with a USB-C cable.
This only applies to Macintosh Plus - later machines already have the diode as standard and will power the FlashSCSI.
Yes, you need to open the Macintosh Plus and solder the diode in, but if you plan on using any classic Mac, you -need- to open it and do an inspection unless you like filling your house with smoke:
Check for paper film caps (usually RIFA brand) and replace on sight with plastic film type.
Check for electrolytic capacitor leakage. If you need to replace the high-frequency bipolar cap, replace it with a 3.9uF 400V+ plastic film type.
Check the yoke windings for corrosion, especially where they're soldered.
Check for cracked solder joints all over the analog board.
I likely stock all these caps but you'll need to ask via email.

Note: By default this comes configured with ideal settings for Mac Plus, which includes a single HDD located at the start of the SD card of size 1,971,322,880 bytes (just under 2GB) (indeed, a filesystem is not used - you can transfer data by making an image of the disk and mounting it in an emaultor such as Mini vMac - as long as you only have a single HDD configured, and have it positoned at the start of the SD, you should also be able to mount it directly on a macOS system).

scsi2sd-util for changing settings (such as drive size and starting location on SD card)
Default settings intended for Mac Plus usage
Based on SCSI2SD v4.2b here
FlashSCSI hardware source files

Useful information about getting started and transferring stuff (take note of the difference between DISK and VOLUME images)