New Disk Emulator - "Tiny SCSI Emulator"

I've always insisted the SCSI2SD was an overpriced piece of garbage, much to the opposition of other folks too wimpy to use real hard drives. Sure it gives you a SCSI disk using an SD card but that's about it and skill wise it's prohibitive for the average person to assemble because of the number of SMD components. Also there was likely going to be better solutions. Something smaller but much more feature packed. Something to tell the SCSI2SD to get bent.

Now there is.   >>>LINK<<<

[David Kuder]’s tiny SCSI emulator is designed for just this purpose. [David] has combined a Teensy 3.5 with a NCR5380 SCSI interface chip to build his device. With a 120MHz clock and 192K of RAM, the Teensy provides plenty of horsepower to keep up with the SCSI signals, and its DMA features don’t hurt either.

Now, many earlier SCSI emulation or conversion projects have purely focused on storage – such as the SCSI2SD, which emulates a SCSI hard drive using a microSD card for storage. [David]’s pulled that off, maxing out the NCR5380’s throughput with plenty to spare on the SD card end of things. Future work looks to gain more speed through a SCSI controller upgrade.

But that’s not all SCSI’s good for. Back in the wild times that were the 80s, many computers, and particularly the early Macintosh line, were short on expansion options. This led to the development of SCSI Ethernet adapters, which [David] is also trying to emulate by adding a W5100 Ethernet shield to his project. So far the Cabletron EA412 driver [David] is using is causing the Macintosh SE test system to crash after initial setup, but debugging continues.

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It's so much better than the SCSI2SD. The link above goes over the details of the project, includes the code to set it up, additional documentation and the board layout so you can get a few fabbed and YES, you CAN solder this one together yourself and it's not a SMD nightmare. It's through-hole!



This is something I'm willing to put my weight behind. There is also the possibility of later a version for substituting the 2.5" SCSI disks in the Powerbooks. THAT holds some serious merit as it can then also be used in some of the other non-IDE laptops from the likes of RDI and IBM.

Something that can replicate the weird proprietary ThinkPad hard drive interface of old would definitely be cool! As would a 2.5" version for PowerBooks.

CelGen said:

I've always insisted the SCSI2SD was an overpriced piece of garbage, much to the opposition of other folks too wimpy to use real hard drives.

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You know, it is in fact possible to express your enthusiasm for something without tearing down something else and coming across like an ass in the process. It's great that someone else is making another SCSI emulator, it's totally awesome that it may at some point include a working Ethernet adapter (but doesn't yet), but:

1: The SCSI2SD has been out there in the real world solving real problems for quite a long time. It's not by any reasonably objective standard "garbage", especially taking into account its *extremely* low price compared to most previous solutions.

2: Using "real hard drives" doesn't make you some sort of hairy chested He-Man compared to all those effeminate girly-men wannabes that are too big-a-sissies to deserve using vintage computers. I mean, seriously dude, grow the hell up.

itsvince725 said:

Something that can replicate the weird proprietary ThinkPad hard drive interface of old would definitely be cool! As would a 2.5" version for PowerBooks.

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What weird proprietary Thinkpad HD interface are you talking about?

Unknown_K said:

What weird proprietary Thinkpad HD interface are you talking about?

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I don't know what it's called, but I know the ThinkPad 360C used it.


The drive itself is probably IDE, but it's encased in this sealed shell with a proprietary IBM connector.

IIRC you can just crack that thing open and install your own IDE drives in it.

IDE! The most insidiously proprietary of all HD formats!

In general, ThinkPads used IDE disks encased in little plastic boxes. You should be able to (with some amount of difficulty, perhaps, because they were meant to be used as swappable modules) pop open that enclosure and take out the drive to replace it with another.

On the topic of the Tiny SCSI Emulator: Do we know how fast it is and what 'retail' availability is? Inertialcomputing and others are already selling the SCSI2SD at imminently reasonable prices for the Mac crowd.

I think that there's market enough for multiple types of devices that do this work. SCSI2SD v6 is said to be a lot faster than the previous versions and should be suitable for people looking for SCSI solutions that are faster and allow for bigger volumes using full-sized SD cards. Could be worth trying in a Power Macintosh or something like an 840. Heck, it'd be neat to see it in something like an SGI/Sun box.

So a common IDE drive then? LOL

Those drive sleds are common in quite a few Thinkpads and are pretty easy to work on (heck I have spares). I would have to say of all the vintage HD sleds for laptops out there the IBM ones are the easiest and probably cheapest to find.

I honestly thought IBM glued/welded them shut to be rude...seems like something a big computer company would do.

The top is just some kind of removable vinyl tape that goes over the side (easy to peal and put back), there are 2 screws in the back that open the lid (don't lose the nuts).

I can't think of a laptop line that is easier to work on, find spares for, or has better documentation (parts lists, operating guides, etc).

Well...a PowerBook version would still be appreciated!

The more solutions the merrier!

I for one am very happy with my several SCSI2SD devices and I appreciate anyone going to the hard work of creating new and useful devices that I couldn't or wouldn't ever develop myself.

have not seen any price tag ?

Like others, price..? It looks great.

This just looks like a proof of concept right now.  Once (or if) it starts shipping and can be compared to the existing solutions then things will get interesting.

I don't understand all the hatred against the SCSI2SD either.  It's not like there are hundreds of folks lining up to develop things for our vintage gear.  Yes, for someone who knows what they're doing putting together something like the SCSI2SD may be a cakewalk but insulting a large group of people is not the way to get a point across.  I prefer real HDs as well but calling people who use solutions like SCSI2SD "too wimpy to use real HDs" is akin to the Windows folks who used to deride Apple users in much the same way ("When are you going to take the training wheels off your computer?"  "Real computers have a command line!")

$100+ for a device when you can still find under $50 (talking working SCSI 50 pin HDs) is a tough sell to me. 10-20 years down the road will be a different story economically.

A cheap SCSI to IDE or SATA sled (maybe for a laptop drive) would be better, but I can see people wanting to ditch spinning disks.

bibilit said:

have not seen any price tag ?

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There's no way it's going to be cheaper than the SCSI2SD, that's for certain, as the materials BOM even if we don't include the Ethernet shield is close to that of an assembled SCSI2SD Rev. 5. There's also no particular reason to believe that this solution will be faster than SCSI2SD, and in fact their current claim of 1.3MB/s at the host PHY is right around the demonstrated capability of the Rev 5 (let alone the Rev 6), so that scratches "performance" off the list of reasons to trash the SCSI2SD as well. It's also probably worth noting that:

A: The only reason it can be all through-hole is because the board relies on hosting pre-assembled modules which are themselves covered with surface mount (and BGA) components. That's great for a prototype but it's possibly not the most practical thing in the world if it were to ever go to production to the extent that the SCSI2SD has, so it's dirty pool to compare them on that basis, and:

B: While not exactly a deal breaker the fact that it relies on old-stock SCSI chips that mostly seem to be available only on eBay as pulls again puts it at a disadvantage compared to the SCSI2SD for mass production.

I'm not saying any of this to trash this product, far from it; it's *FANTASTIC* to have multiple options and the fact is that the goals of this project are obviously somewhat different from those of SCSI2SD: the latter is tightly focused on *just* being a storage solution while this has the potential if all goes well to emulate any number of other interesting SCSI tinkertoys, and that's cool as heck. The point here is only that it's *absolutely, totally, and completely unnecessary to trash the SCSI2SD to make the case for this project*. (Granted I haven't looked particularly hard, but I don't see the creator of this doing that anywhere.) It's childish.

I'd like the SCSI2SD if the developer hadn't dropped all firmware updates to the old version in place of the newer verison, which isn't even that much of an improvement....

Just curious, but what updates to the v5 firmware are needed?