[Coco] 2gig CF card killed

[Joel Ewy]

John Guin wrote:
> Roger,
>
> I've been testing flash devices as hard drives at work for performance
> related metrics.  On a sort of related note, many apps actually run slower
> on flash drives.  They tend to write frequent, small changes to the drive in
> order to save data.  This has the two unexpected affects on flash devices.
> First, since they have to perform a block read before writing any data, they
> don't get the speed increase solid state would seemingly provide.  Second,
> any app which uses a swap file (including the OS) can very quickly burn out
> a flash device.
>
> (Vista ReadyBoost actually accounts for this and limits writes.  A typical
> swap file from Windows/Linux/Unix would not.)
>
>   
I think the ideal kind of OS for installation on CF is something like a
live CD, which is meant to be run from read-only media anyway.  Knoppix,
Puppy Linux, and Damn Small Linux come to mind.  I've installed LEAF
(Linux Embedded Appliance Firewall) on CF and it is just peachy.  Of
course it almost never writes anything, by design. 

The main reason to use CF in place of a hard drive is for embedded
systems, network appliances, or some other use where you want mass
storage that needs to be small, energy efficient, and/or resistant to
vibration.  Something like the aforementioned Linux distros will run
without swap, given enough RAM, or will make swap an option that the
user can switch on when necessary.  These OSes also use all sorts of
cool filesystem tricks so they can overlay changes to what would
ordinarily be a read-only medium on a RAMdisk, and then save the changes
to writable non-volatile storage on shutdown.

If you need swap, or have some other need for a lot of little writes,
use a Microdrive instead of CF.  Same form factor, same interface, still
uses much less power than a 2.5" HD.

I've got some old Pentium 133 laptops that I'd like to squeeze some more
use (and battery time) out of.  My plan is to install Damn Small Linux
on a Microdrive in place of the 2.5" HD.  The best outfitted of these
machines has 80M of RAM.  DSL would manage that amount of memory pretty
well even without swap, but it would be more comfortable enabling
virtual memory with a swap partition on the Microdrive.  50M for DSL,
and 256M for swap, would leave plenty of space for MyDSL apps and user
data on a 4G Microdrive.  Then if I want more (and removable) storage, I
can plug a CF card into a PCMCIA card reader.  (BTW, these old Compaq
P133 laptops run Jeff Vavasour's DOS CoCo 3 emulator nicely.)

On a somewhat more modern laptop with more RAM (say, at least 256M) and
USB ports, I wouldn't be afraid to run DSL entirely from CF and RAM,
either from the perspective of performance or excessive writes.  With
>=128M RAM you can load the entire DSL disk image into RAM on boot and
not touch mass storage at all, even for reading, until you intentionally
save a file or shutdown the machine, whereupon it backs up user data.

So, there are definitely considerations to make when running an OS from
CF.  If you can't get around a high number of writes, you can often
substitute a Microdrive.  But many of the problems encountered with
trying to run a full-blown modern OS from flash memory would likely
remain problems in an embedded or low-resource computing environment
even without the issues involved with writing to flash.  If you're in a
situation where you want CF, you probably also want an OS and
applications that are trimmed down, tightened up, use RAM efficiently,
and write to mass storage only when necessary.
> Does OS-9 use a swap file?
No, (Nitr)OS-9 doesn't use virtual memory.
>   If do, is there any way to limit it writing to
> the drive?  And if it doesn't use a swap file, then I feel pretty
> comfortable saying the flash device would outlast the Coco itself.
>   
I would think that a delayed-write disk cache could help as well.  I
remember using one on the MM/1, but I don't know if there's such a thing
for CoCo (Nitr)OS-9.

JCE

> John Guin
>
> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
> Behalf Of Roger Taylor
> Sent: Friday, March 21, 2008 10:05 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: [Coco] 2gig CF card killed
>
> Well, I think I've successfully killed a nice Lexar 2gig CF card after many
> attempts of installing Windows 98SE on it to run on my Compaq IA-1 internet
> appliance.
>
> The IA-1 was hacked through software by replacing the internal 16mb sandisk
> (originally stocked with MSN Companion, a browser system) with Midori Linux.
> Since the unit can also boot from the CF slot, a FAT-16 formatted card made
> bootable and with MS-DOS system files would boot into MS-DOS, and if Windows
> 98 was installed on the FAT-16 card, it would boot as well.
>
> I was trying different install methods, first putting the Win98SE CD
> contents on the MS-DOS bootable CF card, then running setup.exe from the DOS
> prompt on the IA-1.  This worked perfect up until it kept locking up far
> into the install when the plug and play detection was happening.  Then I
> installed WIndows on the CF from my PC with the CF card connected as IDE
> drive 0, primary, using an IDE to CF adaptor.  This worked great and Windows
> and the PC both thought it was a real drive.
>
> I did so many installs and formats, that I think I reached the ~300,000
> erase/write limit of the card.
>
> My question is, with the IDE interfaces in use and people using CF cards as
> their main CoCo HD, how long would you expect the card to make it as a hard
> drive knowing that the cards were designed with a limited number of writes
> possible, and also when the card reaches this point, is it readable-only
> then?  Mine can't even be accessed now.
>
> It seems to me that more and more people are trying to use CF cards as hard
> drive solutions for embedded systems and even for their computers.  This has
> got to be the business to get into?  :)  Think about it, they've designed a
> card that really shouldn't be any different than a memory stick in what they
> do (store memory and read it), but for some reason the CF's have a dying day
> somewhere in the future, sooner or later, depending on your use.  They know
> very well that people are trying to use them as hard drives on various
> systems, and that unless it's an embedded solution like Windows has done
> with a version of CE to limit the # of commits to the card, it's a dead card
> the day you buy it.  I don't think they're worth messing with.
>
>
>
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