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- Springboard Modules (http://discussion.visorcentral.com/vcforum/forumdisplay.php?forumid=10)
-- What is "Flash ROM?" (http://discussion.visorcentral.com/vcforum/showthread.php?threadid=5211)

Can someone please give me a laypersons definition of "Flash ROM?" I'm clueless.

(I don't know where to post this question. Hopefully I'll find some answers here).

ROM (Read Only Memory) is "burned" at the factory and, in the case of the visor's ROM, contains the operating system and various other applications (memopad, calculator...).

Flash ROM is, for the most part, the same as ROM in that it is originally burned at the factory. The difference is that it has the ability to be re-burned by another application while still in the device (called "flashing" the device). This allows for new versions of the operating system to be put into the ROM without having to change ROM modules. Flash ROM is more expensive than ROM and was not included in the visor so as to keep prices down.

This has become a sore point with a few people as Palm has included Flash ROM in their newer Pilots and the current OS, version 3.3?, is only capable of being installed into devices with Flash ROM. So the only way to update the OS on a visor is with a software patch which resides in RAM and has to be reinstalled each time a hard reset is done.

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Jay

[This message has been edited by frasej (edited 02-09-2000).]

Jay - This is good. I think I'm tracking with you.

Next question. What then is the difference between Flash ROM and Handsprings' 8MB Flash module? Like you mentioned, some Visor users want the Flash ROM, but isn't that what the 8MB Flash module is all about???

Thanks for your help!

Well, sort of. Yes, the 8MB Springboard module uses Flash ROM, but this is different as this is not where the system "boots" from. It always starts from its internal ROM. The reason that Flash ROM is used in the module is so you don't have to have a battery in the module to retain data. With ROMs or Flash ROMs, data is retained even when there is no power. With RAM, as soon as you lose power, you lose your data (try removing the batteries for 1/2 hour and you won't have any data left on your visor). Oh, the reason for the 1/2 hour in my side note above is that the visor has a capacitor that keeps the RAM "hot" for a short period of time.

But back to the original question, you could put patches onto the 8MB module but you couldn't put OS v3.3 onto it and expect it to work. The visor just doesn't go there looking for its OS.

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Jay

Okay - you kind of lost me with the RAM stuff. If I load a bunch of addresses into my Visor (BTW - I don't own a Visor)and then take out the batteries for 1/2 hour, I'll lose all those addresses???

Also - what's the difference between the 8MB Flash Module and the Backup Module, besides $40? They seem like the same thing to me. You store data on both of them, right? And this data can be accessed whenever, right?

Lemme try explain:

In the traditional computer sense, RAM is the memory that gets erased when the machine powers down. It is fast; in fact it's the fastest form of memory available. ROM are "burned" at a factory, much like a CD. I believe access time for ROM is about the same as RAM, though one might be faster.

Using the CD-ROM analogy, FlashROM is like a CD Rewritable. It can be rewritten by a software, or end user. In a hand held enviroment, Flash ROM is used for loading the operating system; something that doesn't need to be done much often. In fact, PalmOS 3.1H which is loaded on all Visors already have most of the patches for Palm 3.3 installed.

FlashROM is expensive, so it's use is minimal. That's why it's not included at all in the Visor. The user's memory is actually RAM. The Palm Device requires the battery to keep it alive, and a capacitor to keep it hot while you change batteries. The power consumption is EXTREMELY low, and a Palm OS device can keep it's memory in the "off" state for over a year, without memory loss. For all pratical purposes, this implementation is not obvious to the consumer (except to make the device cheaper).

So, yes, if you pull the batteries out, and let it sit for half hour, you will be losing data. But if you are most hand held users, you'll be replacing the batteries right away when you're changing batteries, and you hotsync, which backs up the data onto a machine anyway.

Flash cartridges are flash rom cartridges (I believe - someone correct me if I'm wrong). That's why the 8Mb cartridge is so expensive, you'll notice that it's almost $10.00 per Mbs. They act as an extension to the Visor's 8Mb existing, but don't need a battery (or power from the Palm device) to be kept alive (again, someone correct me if I'm wrong).

The difference between the 8Mb Flash and the 8Mb backup is that the 8Mb backup is designed to just make a mirror image of the 8Mbs of memory in the visor. In other words, you load the cartridge in, press a button, and bam, it makes a copy of what's there. There's no real intellgence in the cartridge (and I am not too sure what type of chips it uses). OTOH, the 8Mb Flash is designed to be almost like an external drive to the visor; there's actually a program that runs on insertion that notify the system what files are on the 8Mb cartridge. You can then selectivelly load data or documents off the 8Mb flash cart.

Hope this helps.

-=- SiKnight

Ahhhhhhh, now I see the light. This all makes perfect sense. Thanks a ton to both Jay and SiKnight.