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H/PC Oracle Posts: | 16,175 |
Location: | Budapest, Hungary | Status: | |
| Quote deusexaethera - 2007-09-23 4:25 AM
I have 128MB of RAM (though only 80MB is available for allocation, I have no idea why), 10MB of internal FLASH (or maybe it's EEPROM, I dunno), and that's it for now. I've got a 6GB card coming in the mail.
80MB, because the rest is used by the whole OS image loaded into RAM (extracted from NAND and then loaded on boot )
10MB? it's flash, nand flash, not eeprom | |
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| Damn, so it doesn't run the OS straight from ROM? Too bad, though I suppose that would make it more complicated when files get overwritten.
Anyway, what threw me off about the type of internal storage is that the MobilePro claims to have a 32MB EEPROM available to the user. Either that, or they described it inaccurately.
Edited by deusexaethera 2007-09-23 1:06 AM
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H/PC Oracle Posts: | 16,175 |
Location: | Budapest, Hungary | Status: | |
| it can't, because the flash is not NOR, so cant execute from place.
overwriting files was never a problem, they are shadowed. even though the OS is in ram, if you attempt to overwrite a OS file, it will just get shadowed, not real overwrite, so if you delete the new version of the file the original one comes back
again, it isnt EEPROM, it is NAND. for both 900c (userdisk ) and netbook pro 
whats the problem btw? cant see the 32MB on your 900c? or..? Edited by cmonex 2007-09-23 2:26 AM
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| There wasn't a problem.
On a different note, you said in another thread that I will eventually learn how indispensable CF cards are. I know how useful it is to have extra storage, but if I install apps on a CF card, what am I supposed to do if I need to swap a different CF card in temporarily? | |
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| Quote cmonex - 2007-09-23 2:24 AM
it can't, because the flash is not NOR, so cant execute from place.
...
again, it isnt EEPROM, it is NAND. for both 900c (userdisk ) and netbook pro This is from the NEC MobilePro 900c user's manual.
Memory:
- 64 MB of SDRAM standard (100 MHz )
- 32 MB of Flash ROM + 32 MB of Flash ROM; NAND or NOR
Flash type (the additional 32 MB of Flash ROM may be used to
flash applications to field devices )
I'm not saying that I definitely have NOR FLASH built in, but I don't think the type of circuit makes a difference; the chipset should abstract that for the CPU's benefit, anyway.
Anyway, what I meant before about being disappointed that the entire OS image gets loaded into RAM, is that I expected files would be copied into RAM on an as-needed basis. But, as previously noted, I guess that would make it difficult to resolve conflicts between "overwritten" files in ROM -- there would have to be a check, every time a ROM file is accessed, to see whether a duplicate file exists in storage RAM. I guess it's easier to make a working copy of the entire ROM instead. | |
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Global Moderator H/PC Oracle Posts: | 12,674 |
Location: | Southern California | Status: | |
| Quote deusexaethera - 2007-09-23 7:42 AM
There wasn't a problem.
On a different note, you said in another thread that I will eventually learn how indispensable CF cards are. I know how useful it is to have extra storage, but if I install apps on a CF card, what am I supposed to do if I need to swap a different CF card in temporarily?
With more than one slot, you should almost never have to do that. If you need to use another CF card, you can use it in the PCMCIA slot with a PCMCIA-to-CF adapter.  | |
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| Heh...oh yeah...forgot about that. I was thinking I'd put the wireless card in the PCMCIA slot and never take it out again, I guess. 
Still, for the sake of argument, what would I do if I had to use the machine without its CF card installed? Edited by deusexaethera 2007-09-23 2:00 PM
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Global Moderator H/PC Oracle Posts: | 12,674 |
Location: | Southern California | Status: | |
| That's the rare case when you need to use RAM. For example, I put iBIZ pocket RADIO in \Program Files on several of my H/PCs, so that I have the option of listening to the radio while browsing the Web. | |
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H/PC Oracle Posts: | 16,175 |
Location: | Budapest, Hungary | Status: | |
| Quote deusexaethera - 2007-09-23 4:53 PM
This is from the NEC MobilePro 900c user's manual.
Memory:
- 64 MB of SDRAM standard (100 MHz)
- 32 MB of Flash ROM + 32 MB of Flash ROM; NAND or NOR
Flash type (the additional 32 MB of Flash ROM may be used to
flash applications to field devices)
I'm not saying that I definitely have NOR FLASH built in, but I don't think the type of circuit makes a difference; the chipset should abstract that for the CPU's benefit, anyway.
Anyway, what I meant before about being disappointed that the entire OS image gets loaded into RAM, is that I expected files would be copied into RAM on an as-needed basis. But, as previously noted, I guess that would make it difficult to resolve conflicts between "overwritten" files in ROM -- there would have to be a check, every time a ROM file is accessed, to see whether a duplicate file exists in storage RAM. I guess it's easier to make a working copy of the entire ROM instead.
1. it has both nand and nor. nor is where the OS image is stored on the 900c. 32mb.
the nand is the userdisk, 32mb.
so you have nor and nand too.
2. only the netbook pro loads it to ram, 900c doesn't  900c does copy to ram only on demand. (and sometimes can even xip from rom )
and i already explained it is no problem with "overwriting". the system does keep track to see if there is a duplicate in ram. it is not hard to do.
also, even though the entire OS is copied to ram on the netbook pro, the system still does the checking for duplicates, it will NOT overwrite anything in the loaded OS image, it treats it as rom. hope it is more clear now.
you could then ask why the heck does it copy the whole OS in ram then. it is because the OS image format is XIP which wont work from nand (the netbook pro only had nand ). i guess they didnt have an option to use imgfs or some other OS image format to load the stuff only on demand. Edited by cmonex 2007-09-23 2:53 PM
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H/PC Oracle Posts: | 16,175 |
Location: | Budapest, Hungary | Status: | |
| Quote deusexaethera - 2007-09-23 4:42 PM
There wasn't a problem.
On a different note, you said in another thread that I will eventually learn how indispensable CF cards are. I know how useful it is to have extra storage, but if I install apps on a CF card, what am I supposed to do if I need to swap a different CF card in temporarily?
stop the apps running from CF first, then swap the CF's, then back.
or do what CE Geek said | |
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| Quote cmonex - 2007-09-23 2:49 PM
2. only the netbook pro loads it to ram, 900c doesn't 900c does copy to ram only on demand. (and sometimes can even xip from rom )
...
you could then ask why the heck does it copy the whole OS in ram then. it is because the OS image format is XIP which wont work from nand (the netbook pro only had nand ). i guess they didnt have an option to use imgfs or some other OS image format to load the stuff only on demand. You know way too much about this stuff, man. You need to get outside more. Maybe meet a girl. 
Why does the type of memory circuit matter as far as whether the system can boot from it? As far as I knew, the only benefit to NOR was it was faster, or something like that. | |
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H/PC Oracle Posts: | 16,175 |
Location: | Budapest, Hungary | Status: | |
| Quote deusexaethera - 2007-09-24 2:27 AM
You know way too much about this stuff, man. You need to get outside more. Maybe meet a girl.
lol.. i'm not .... that type.  btw, i somehow have a feeling you are a girl too?
(and no, i dont know the very low level details of how the different types of memory etc. work, so maybe i don't know that much. )
Quote
Why does the type of memory circuit matter as far as whether the system can boot from it? As far as I knew, the only benefit to NOR was it was faster, or something like that.
it matters because it matters how it is exposed to the cpu. nor is like real memory to it, can access it directly, nand is like a disk with a controller.. thats it in some simple words at least.
(when you start wondering about how a nand pda can be booted then, well there is a special part of it that is bootable, loads some small code then that code loads the rest into ram ) Edited by cmonex 2007-09-23 8:45 PM
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| Quote deusexaethera - 2007-09-22 10:25 PM
I don't know what PSA means.
I have 128MB of RAM (though only 80MB is available for allocation, I have no idea why), 10MB of internal FLASH (or maybe it's EEPROM, I dunno), and that's it for now. I've got a 6GB card coming in the mail.
Why would FAT16 be faster than FAT32? Dammit, every time I think I understand filesystems... I ask again, why would FAT16/512B/4kB be faster than FAT32/512B/4kB? All of the stats are the same, aren't they? | |
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| Quote cmonex - 2007-09-23 8:43 PM
lol.. i'm not .... that type. btw, i somehow have a feeling you are a girl too?
(and no, i dont know the very low level details of how the different types of memory etc. work, so maybe i don't know that much. ) Last I checked, I'm definitely not a girl.
Quote cmonex - 2007-09-23 8:43 PM
it matters because it matters how it is exposed to the cpu. nor is like real memory to it, can access it directly, nand is like a disk with a controller.. thats it in some simple words at least.
(when you start wondering about how a nand pda can be booted then, well there is a special part of it that is bootable, loads some small code then that code loads the rest into ram) How strange. I thought all memory, whether volatile or non-volatile, has to be accessed through a memory controller of some sort. Shows what I know, I guess.
But, on the bright side, I know there's at least one woman in the world who's as much of a geek as I am. 
(maybe more so.  ) Edited by deusexaethera 2007-09-24 11:45 AM
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H/PC Oracle Posts: | 16,175 |
Location: | Budapest, Hungary | Status: | |
| Quote deusexaethera - 2007-09-24 5:38 PM
Quote cmonex - 2007-09-23 8:43 PM
lol.. i'm not .... that type. btw, i somehow have a feeling you are a girl too?
(and no, i dont know the very low level details of how the different types of memory etc. work, so maybe i don't know that much. ) Last I checked, I'm definitely not a girl.
Quote cmonex - 2007-09-23 8:43 PM
it matters because it matters how it is exposed to the cpu. nor is like real memory to it, can access it directly, nand is like a disk with a controller.. thats it in some simple words at least.
(when you start wondering about how a nand pda can be booted then, well there is a special part of it that is bootable, loads some small code then that code loads the rest into ram) How strange. I thought all memory, whether volatile or non-volatile, has to be accessed through a memory controller of some sort. Shows what I know, I guess.
But, on the bright side, I know there's at least one woman in the world who's as much of a geek as I am.
(maybe more so. )
heheh @ bright side comment
(sorry for assuming you were female, just got that feeling from some stuff )
as for memory controllers, of course there is some sort of that stuff but the cpu can directly address the ram and nor flash, and can't nand, only through another controller.
i dont know the low level tech details on this though. all i saw was some disasm for nand reading, where the cpu accessed it through a controller's data register for reading (after setting up some other nand registers ).
p.s.: i am definitely planning to get more info on nand, want to write a low level nand dumper once, for some hpc's. Edited by cmonex 2007-09-24 1:34 PM
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