CompactFlash hard-drive?

[Cloudschatze]

Anyone out there using solid-state CompactFlash cards as hard-drives?

I am working on replacing the (horribly) noisy 3.5" hard-drives in my mini PCs, and had hoped to do so with IDE-CF adapters and Microdrives. After purchasing a couple of rather nice adapters, I somehow missed the fact that they cannot physically accept a CF Type-II card (without modification). Having used a Microdrive in an Apple IIGS to much success, I had hoped to stick with the same format, but might I be just as well off with a NAND-based CF card? With an endurance rate of 300,000 write cycles, would such a card be acceptable for an old, DOS system? Ultima 7 does quite a bit of disk writing, as I recall...

[BlueMax]

Apparently they just developed a laptop hard drive that's 30-40GB and uses FLASH RAM!  Yep!  It's faster, impervious to physical damage (well, vastly better than a 2.5" HDD) and not ridiculously expensive.

Keep your eyes on that baby for the future!

In the meantime, I know some people are definately doing it.  Any IDE card reader and the biggest, fastest flash card you can get would be very nice.    A modern motherboard should be able to boot from it without issue.....  but I've never done that personally.

[Cloudschatze]

So here's a picture of the completed project. Pardon the electrical tape, but I cheaped-out on the additional $13 it would have cost for a mounting sled.

The manufacturer of the IDE-to-CF adapter needs to update their website. It turns out that the revision that I received will accept Type I and II cards. With this revelation, I plan to continue using the NAND card in this PC, and will use a 1gb Microdrive in the other.

So quiet, aah...

[Cloudschatze]

I installed the Microdrive in the other PC today, and am not very happy with the result. Whereas the NAND card performs wonderfully, the Microdrive has a read/seek latency akin to CD-ROM access. Ugh.

[gortmertl0]

I installed the Microdrive in the other PC today, and am not very happy with the result. Whereas the NAND card performs wonderfully, the Microdrive has a read/seek latency akin to CD-ROM access. Ugh.

Any ideas as to why there seems to be a few CF-to-IDE adapters/converters, but none for other types of Flash Media?

Is it based on the design of the CF?  Does CF offer advantages that other types of media don't?  Is it that others are proprietary in some way?  Is CF far more popular than other types of media (the IBM/Windows of flash media)?

Just curious, as I find this to be a very intriging idea...

G

[Laust]

CompactFlash was designed to be IDE compatible, so it takes almost no extra hardware to make an IDE to CF adapter (all you need is a CF socket and a normal IDE connector and then connecting them correctly). For other types of flash media you would need a microcontroller (or at least an advanced controller chip) to go between the PC and the flash card, increasing the complexity (and price).

Some modern machines are capable of booting from other types of flash, eg. USB devices.

[Cloudschatze]

Here are the performance values for the NAND-based CF card:

Data Transfer Rate To/From Flash - 20.0 MB/sec burst
Data Transfer Rate To/From Host - 16.0 MB/sec burst


And for the Microdrive:

Media transfer rate - 37.8 to 58.6 Mbits/sec
Interface transfer rate - 13.3 MB/sec


Am I correct in assuming that the Microdrive would need a media transfer rate of ~160 Mbits/sec to equal that of the NAND card? If so, is this a likely reason as to why I am seeing such comparatively poor performance with the Microdrive?

[Laust]

Well, "burst" is not precisely defined... For large transfers, the NAND might not do so well.  There's no denying that the Microdrive is slow, however. Depending on how old your machine is, it might not be an issue at all (apart from slow seeking times perhaps). On a 486 class machine, the IDE controller/CPU will probably be the actual bottleneck. Installing a diskcache should help but I'm guessing you have already...

It would be more interesting to see actual performance ratings. Maybe run a DOS based disk performance test tool (Norton Utilities used to have one, but there are countless others).

[Cloudschatze]

I tried a couple of performance utilities, but wasn't very enlightened by the results. One utility supposed that both drives were nearly identical performance-wise, whereas actual use proves the opposite.

It's plain to me that the NAND cards are a great way to go, both in performance and cost. Though write-cycles may be an issue, it's easy enough to make a backup of the entire disk, and SanDisk will replace the cards, under warranty, should they ever exhibit any catastrophic error rate.

One last hurrah:

Unconditional format with NAND card - 4 seconds.
Unconditional format with Microdrive ~ 4 minutes.

[Cloudschatze]

So, while everyone else was busy buying their 'Tendo's and stuff this past Black Friday, I did what any real geek might, and bought a couple of 2GB CompactFlash cards for cheaps.

Installing one in the Aquanta system proved to be fun. Unlike the smaller 486s, I needed to suspend the IDE interface beneath a component tray. In the end, I ended up cannibalizing an old hard-drive for it's mountable bottom-plate.

I think it turned out rather well...



The visible scraping is the result of having to remove the center "depression" that the drive motor sat within. Being somewhat cheap, and without a hacksaw, I spent two quality hours perfecting the art of metal filing. 

[glendower]

Looks good!

Yeah, microdrives are pretty dang slow. At the time, you couldn't beat the price/MB compared to CF cards, but now there isn't much of a reason to use one. I have a 2GB drive and that was fine for a camera with a big buffer. I didn't realize that they were THAT slow, though. When transfering images to my computer, there was a noticeable difference in speed, but they seem to do okay in that sort of linear, non-random transfer.

[Cloudschatze]

Tandy 1000SX w/286 Express - $1.99.
Silicon Valley ADP50L(T) 8-bit IDE interface - $0.49.
Addonics CF-to-IDE adapter - $23.99.

340MB Microdrive in a twenty year old Tandy computer - Priceless.

[Ari]

Amazing! 

[gortmertl0]

Congratulations!

That is really something! 

Gary

[Erasmus]

Nice!!!!!

I want to install one of these in my Pentium 166mmx.

http://www.syba.com/product/43/10/13/index.html

Then plug a 2GB high speed Compact Flash in. The other advantage it has, I can easily copy files onto it from my other system via a card reader rather than having to network the two systems together!

The next step is to add very quiet cooling fans to the CPU and power supply. Then I'll have a nearly silent system!

[Cloudschatze]

The other advantage it has, I can easily copy files onto it from my other system via a card reader...

Bingo.

[Great Hierophant]

Silicon Valley ADP50L(T) 8-bit IDE interface - $0.49.  There is the crux, few of us will ever enjoy the attainment of such a device at that low price. 

[Cloudschatze]

Silicon Valley ADP50L(T) 8-bit IDE interface - $0.49.  There is the crux, few of us will ever enjoy the attainment of such a device at that low price. 

Incredibly, I had no idea that it contained the Tandy ROM when I bid on it. Dumb luck at its finest.

[Great Hierophant]

I assume that the drive tables and hard drive BIOS extension are within the ROM on the 8-bit card, and the Molex connector was there in case the power supply did not have a spare, which is quite common in 80s machines.  I'm sure there is a way to build an adapter out of TTL chips.  Does a Tandy require a special BIOS chip?

[Laust]

What exactly is the point of the Molex connector? it's no substitute for a similar connector from the power supply, since the amount of current you can pull off the ISA bus is tiny compared to the PSU. And these are harddrives we're talking about...