Wanna see something weird?
Behold the weird thing!

So it's got an Altera EP1810LC-45, that's a CPLD (which are kind of proto-FPGAs).
The chip next to it is an Intel 80C452, which is an 8051 (TAKE A DRINK) designed for I/O use.

And these are HM628128LFP-12s.
Those are SRAM chips, 128 kilobytes each.
And there's 16 of them.
So whatever this is, it's got two megabytes of SRAM on it.

And next to that, there's these chips, which are Intel P28F020-150 Flash chips.
Those are 256 kilobytes each, and there's 8 of them... so we're at 2 megabytes again.

The back has some info on it, but hidden by this zip-tie that's holding the batteries on.
Eh, I gotta replace those anyway, let's chop it off.

And we've got info! Kinda.
It's got IO, a BIOS, DMA, and it's... bootable?

Wait.
Is this a hard drive? Let's search that name: MemTech PCB902

And yeah, a 1994 release of "The Ref" guide to hard drives, says it's a Plug-In Solid State Disk.

This is an ISA SSD!

A two megabyte SSD!

So I think how it works is that it has SRAM for the main storage.
SRAM needs power, so it has battery back up... but if that fails, it reloads the data from Flash?
Or maybe the battery is just there so it can write to the flash in case of power-loss?

And this weird under-documented early SSD wasn't weird enough... I have two of them!

The second one has the same model number and everything, but it has half as many chips.
So I guess it's a 1 megabyte SSD.

I opened up one of the battery packs.
They're 7 AA-sized NiCad cells.
NiCad is 1.2v when charged, so that's 8.4v

Sanyo CADNICA.
N-600AAK. 600mAh.

So the thing has two EPROMs on it.
I think one might be code for the microcontroller, and the other is the BIOS-extension for the PC, to let it know how to talk to this thing.

the probably-microcontroller one was covered up, but the other one was uncovered. it may have gotten erased.
When I can find my EPROM programmer I'll dump them both. I don't want to plug it in until I at least try to dump both of them.

The flash chips are in sockets, I may be able to pull those out and and dump them directly.

Amazingly the battery I didn't tear apart is still showing 7.4v.
So it probably hasn't been running the SRAM for... years.
it's probably just temporarily used to dump the SRAM to flash, then it turns itself off.

I'm hoping one of those BIOS chips still has data. Because this thing is gonna require drivers to talk to, and having a BIOS makes sense for it: it has to be able to boot off itself since it doesn't work as an IDE drive or anything.

So likely the only documentation of how you talk to it is on those BIOS chips themselves.

Which is why I'm really hoping they work.

well, "work" isn't the right word.
I'm sure they work.
The question is: have they been erased by inadvertent light exposure, since they weren't covered up?

I haven't been able to find any info about this device elsewhere.
MemTech was an Intel spin-off, originally doing bubble memory.
They were acquired by STEC in 2005.

I'm also not sure when this thing came out.
The first reference I see is from 1994, but it could be long before that.
The chips mainly say 1990, so it's somewhere in that 1990-1994 range.

Found the EPROM programmer. Dumped the EPROMs, they seem to be fine.
Started dumping the flash chips... and the first one has PC-DOS 3.30!

Happy #DOScember, everyone.

Amazingly, I dumped the 1mb one first, and it's nearly empty.
There's only like 64kb of boot disk files on it.

Found an article from 1994 that says they were selling them in 2-32mb models, with the 32mb model costing 2584$ (4600$ today)

ahh, 1996, when every site looked like this

Here's a document from their 1996 page.
They're listing a PCF932, which is not the same. I think this is the one talked about in the 1994 article, since it's available in 2-32mb models.