semi
Junior Member
Posts: 97
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Post by semi on Feb 20, 2008 11:05:19 GMT 1
I searched the forum and I can't seem to find the answer I am looking for, so I am making this post to ask about this question which may have been answered already a long long time ago (more than 1000 days ago maybe?) 1 - With ROMs zipped, it would take a bit longer to load than unzipped, correct? (seems that way to me after I zipped the ROMs) 2 - When loading the zipped ROMs, does it mean that it requires less memory to play the game than unzipped ROMs? or the PDA still uses the same amount of memory as the unzipped ROMs? 3 - It seems that WinRAR can compress the ROM even more than WinZip, so just wondering, how come LJP is supporting ZIP instead of RAR? something to do with loading time of the game? or RAR is too complex for PDA to handle? Just finished zipping up all the ROMs I have for LJP, which is good for saving some more space on my memory stick, I did notice it seems to take just a little bit longer to load some games with original file size that is larger, but no biggy about it, only a little bit slower, but I really want to know about question #2, so if Tinnus or metaview can answer this question for me, that would be wonderful, much appreciated  |
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Post by metaview on Feb 20, 2008 16:01:32 GMT 1
Preface: using zipped-ROMs means LJP will extract the content in the memory for you.
#1 yes, as the content needs to be extracted before use
#2 no, it takes even a bit more, as (parts of) the zipped file and the result are hold in memory at start
#3 zip is well known and there exist a widely used open-source implementation (libzip) for almost any device
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Post by Tinnus on Feb 20, 2008 22:50:02 GMT 1
The biggest ROM size LJP would require is 4MB for Genesis and SNES, which shouldn't make #2 a problem if UDMH(-like) functionality is present. And we need it anyway to run those modules I *could* implement ROM paging in LJX, but due to these small sizes, it shouldn't make a difference. Although something like GBA and N64, which can have ROMs with sizes up to 32MB, needs paging in a portable, like the PSP does |
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semi
Junior Member
Posts: 97
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Post by semi on Feb 21, 2008 7:53:01 GMT 1
The biggest ROM size LJP would require is 4MB for Genesis and SNES, which shouldn't make #2 a problem if UDMH(-like) functionality is present. And we need it anyway to run those modules I *could* implement ROM paging in LJX, but due to these small sizes, it shouldn't make a difference. Although something like GBA and N64, which can have ROMs with sizes up to 32MB, needs paging in a portable, like the PSP does Please do~~~!!  I asked #2 was because when I was using Firestorm (I know, it suck), there was a game which is 16MB, if I want to run it, I would have to do a hard reset and install only Firestorm and UDMH, since my Clie NX80V only have 7MB of dynamic and 16MB storage, just enough to play it, so I was wondering about this for LJP/LJX. |
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Post by Tinnus on Feb 21, 2008 13:06:53 GMT 1
As I said, that's 16MB of free contiguous RAM, and something big. The most we need is 4MB for Genesis and SNES, and the modules themselves also require around 4MB for the emulator stuff, which is "in the other side" of requiring UDMH most of the time.
If paging was implemented, I don't think I could reduce the 4MB requirement to something smaller than, say, 2MB or maybe 1MB, or it would just keep swapping parts of the ROM all the time.
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Post by _Em on Feb 21, 2008 17:55:39 GMT 1
As for "why Zip?" there are a number of good answers. Zip uses a block-based compression scheme, so you can read/decompress the files block by block if you want to instead of having to decompress the entire file before reading like you have to with RAR. Plus, RAR is a closed-source proprietary algorithm. That being said, if we're already decompressing the entire file into RAM before using it, 7zip would be a really good option to add, especially since goodtools etc. now have the option of having merged sets using 7zip. That being said, I'd prefer paging and per-block decompression of zip files be implemented 7zip isn't really known for being memory friendly anyway. For anyone wanting to make their zip files smaller, get a copy of zipmax and the associated executables -- read the documentation to see how to set it all up. You can end up with MUCH smaller zip files than you'd get just using winzip. |
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semi
Junior Member
Posts: 97
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Post by semi on Feb 21, 2008 22:29:40 GMT 1
As I said, that's 16MB of free contiguous RAM, and something big. The most we need is 4MB for Genesis and SNES, and the modules themselves also require around 4MB for the emulator stuff, which is "in the other side" of requiring UDMH most of the time. If paging was implemented, I don't think I could reduce the 4MB requirement to something smaller than, say, 2MB or maybe 1MB, or it would just keep swapping parts of the ROM all the time. Not sure if I get you right, but it seems to me like you mistaken me that I want to have ROM paging for Genesis and SNES... Just in case if you think I am, as a matter of fact, I don't.. my Clie can handle Genesis and SNES without UDMH at all, I was refering to having ROM paging for GBA, sorry about the confusion, didn't mean it |
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semi
Junior Member
Posts: 97
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Post by semi on Feb 21, 2008 22:32:10 GMT 1
As for "why Zip?" there are a number of good answers. Zip uses a block-based compression scheme, so you can read/decompress the files block by block if you want to instead of having to decompress the entire file before reading like you have to with RAR. Plus, RAR is a closed-source proprietary algorithm. That being said, if we're already decompressing the entire file into RAM before using it, 7zip would be a really good option to add, especially since goodtools etc. now have the option of having merged sets using 7zip. That being said, I'd prefer paging and per-block decompression of zip files be implemented 7zip isn't really known for being memory friendly anyway. For anyone wanting to make their zip files smaller, get a copy of zipmax and the associated executables -- read the documentation to see how to set it all up. You can end up with MUCH smaller zip files than you'd get just using winzip. Thank you for the detailed answer, understood now and I will take a look at that zipmax to see if I can shrink the file size a little more (every little bit helps when you have lots of ROMs) |
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I asked #2 was because when I was using Firestorm (I know, it suck), there was a game which is 16MB, if I want to run it, I would have to do a hard reset and install only Firestorm and UDMH, since my Clie NX80V only have 7MB of dynamic and 16MB storage, just enough to play it, so I was wondering about this for LJP/LJX.
