RASCSI, an affordable SCSI emulator based on a Raspberry Pi
A solution has been available for a long time for replacing old SCSI hard disks that no longer function.
I am referring here to SCSI2SD , which is an interface that has been around for quite a few years and fulfills its role perfectly.
There is only a small disadvantage, namely the price tag, prices vary from 75 euros for an old model to 150 euros for one of the new(er) models.
There was once an attempt to build a SCSI emulator based on an Arduino / raspberry Pi.
That never really took off as compatibility with hosts other than what it was designed for was virtually nil.
Fortunately, the project was picked up by Akuker, who developed it with a team of developers into an all-round SCSI emulator with a lot of functionality, but more about that later.
RASCSI, about Gerbers, SMD and DIY that isn't DIY.
The Gerbers can be downloaded from the project's GitHub page, so that you can make your own RASCSI PCBs.
Unfortunately if you want to start it yourself you will have to have a very steady hand, and a pair of eagle eyes.
They have chosen to make use of 402 SMD components, 402 is really so miniature that if you put a pair of tweezers on it, you no longer can reach the component to solder it.
So if you want to have a board made you will either need a reflow oven yourself, or you will have to have it soldered by the PCB manufacturere (if they offer such a service).
58 resistors are used alone in the 402 size, which is an impossible task for a normal person to solder by hand.
RASCSI , SMD not do it yourself, now what?
Why the hell they chose to do it in this miniature format is a complete mystery to me.
A : this interface replaces a 3.5 or 5.25 inch hard disk, so why miniature?
B : Prices for SMD components are in the numbers that an end user buys, nothing cheaper than the regular TH components, rather more expensive.
People who know me know that I have a problem with (Unnecessary) SMD use, simply because the editing is not very friendly, is difficult to repair and above all it looks out of place in the old technology for which it is intended.
(Add to this that when you are old, you do not have a steady hand and less good eyes, but that aside) 🙂
RASCSI , PCB then make a useful design yourself :
I've been messing around with soldering, designing and building PCBs for about a year and a half and slowly but surely I'm getting better at it.
When I saw the schematics and the design of the PCB I knew immediately that it wasn't going to be it.
Getting started with my own package and after a night of messing around I had a first prototype ready of my version of the RASCSI implementation.
After checking it a few times and making some minor changes to the layout
I sent the design for production to JLCPCB who quickly and perfectly made it from design to PCB.
When the PCBs were ready, and sent to me, it felt like if they had to be brought to the Netherlands by a rowing boat 🙂
But when they finally arrived , the build-up could begin, I had already received the components in the meantime, so I could go straight to building up one of the newly received PCB's.
No sooner said than done, everything went exactly as I had in mind, and when the board was ready and I could start testing, it turns out i misplaced my SCSI controllers... somewhere in a movingbox in the attic.... sigh.... we talk about a salvage operation to which the salvage of the Titanic is compared to a Sunday afternoon outing.
Well then i simply bought 2 SCSI controllers on a local craigslist thingy (Marktplaats) , a person can never have enough SCSI controllers, right?
So when the SCSI controllers arrived, I could finally put my own design of the RASCSI to the test.
First put a Rapsberry Pi 3A+ (which is actually intended for my PiStorm) under the RASCSI interface
Downloaded the software (Ready-to-use image available) and flashed it onto the SD card
Booted up from the RASCSI with the Pi underneath, set up WiFi
and after that everything else could be done remotely, creating hard disks (standard harddisks, named harddisks (if your system only supports a type/brand of harddisk), CD-ROM images and even ethernet over SCSI is possible.
Very intuitive, in 5 minutes I had mounted the harddisks and a CD-ROM image, rebooted the pc and could use the newly created SCSI disks.
After that i placed the RASCSI interface on a Pi ZERO II , plugged in the already configured card and it was good to go, no reconfiguring or whatever (Pi zero II and Pi 3 are in a lot of ways the same)