To: opendos AT delorie DOT com Date: Mon, 3 Jul 2000 19:08:19 -0700 Subject: Re: Of large disks (Was Re: Fw: PTS-DOS) Message-ID: <20000703.193645.-752193.1.domanspc@juno.com> X-Mailer: Juno 4.0.9 MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Juno-Line-Breaks: 0-6,8,10,12,14,16,18-19,21,23,25,27,29,31-32,34,36,38-40,42,44,46,48,50,52,54,56-58,60-90,92-95,97,99-102,104,106,108-116 X-Juno-Att: 0 X-Juno-RefParts: 0 From: Robert W Moss Reply-To: opendos AT delorie DOT com I hope some of this info swiped from 11ED of Upgrading and Repairing PCs is if some help. BOB "DOMAN" MOSS -------Be a Chocoholic-------- Default cluster sizes for FAT12/16 are: 0MB to under 16MB 8 sectors or 4096 bytes 12-bit 16 through 128MB 4 sectors or 2048 bytes 16-bit 129 through 256MB 8 sectors or 4096 bytes 16-bit 257 through 512 MB 16 sectors or 8192 bytes 16-bit 513 through 1024MB 32 sectors or 16384 bytes 16-bit 1025 through 32768 64 sectors or 32768 bytes 16-bit Even if the 2-byte cluster size field could contain the value indicating 64KB clusters, the maximum partition size would still be constrained. The maximum partition size would be limited by the field in the disk parameter block that specifies the number of sectors per cluster. This field is only one byte long and its value must be a power of two. This makes its highest possible value 128 sectors, which equates to a maximum cluster size of 64KB. 65,536 at 64K each equals a maximum partition size of 4GB. The effect of larger cluster sizes (for Bernie) on disk utilization can be substantial. A 2GB partition containing about 5000 files with average slack of one-half of the last 32KB cluster used for each file, wastes over 78MB [5000 x (.5 x 32) KB] of file space. Looking at the above you would say that 256MB or 512MB would be the best sizes for a partition, but a lot of new programs out there use more than 512MB just to install the program, and then you have to set up a location for data files. In that case the best size would be the size required for the program files and a separate 128MB partition for data files IMHO since there can not really be an ideal partition size. Besides, most of the computer users out there in the real world are not power users and care less about all this so they like to have as few distractions as possible when using the computer. Most of them would prefer to have only one drive to worry about. On Mon, 3 Jul 2000 17:06:45 +0200 (MET DST) Bernie writes: > Arkady wrote: > > FAT16 limit is an 2G (really 4G, but MS restricts cluster size > by 32K > >instead of 64K). > > On one partition yes. Jikes, 64K clusters - no wonder they > restricted it to > 32K, 512MB partitions are perfect IMHO. > All clusters in FAT32 OS are : 0MB to under 260MB 512 bytes 260MB through 8GB 4096 bytes 8GB through 16GB 8192 bytes 16GB through 32GB 16384 bytes 32GB through 2TB 32768 bytes Here again you might want to have 260MB partitions for data files and 8GB for program files. > > > Or have I completely misunderstood this? > > > > Yes. FAT limited in size (FAT16 - 2G, FAT32 much more), but > not in > >position, which can be higher 8G. > I'm not a professional programmer myself but I believe it would take a "fairly long time" for a team of 10-12+ programmers working voluntarily, in their spare time, to write [from scratch] a program to emulate or better the FAT 32 system. This is not something to sniff at as even the great Bill Gates had to go out and buy a "Bootleg" copy of Digital Research's CPM which had been modified as a "quick and dirty" system to run on the Intel 80XX chips, that he then LEASED to IBM. One of the problems with OS's is the ability of the owner of the most used OS to build into the system a few "dirty tricks" which make programs crash when another OS (DRDOS) is used to run the computer, hence one of the reasons for DRDOS's lawsuit against uncle Bill. Anyone wanting to sell a OS compatible with MSDOS has to pay 9 figure licensing rights fees to MS, but DRDOS wasn't invited to the party and IBM was. That's also one of the reasons Novell bailed out on DRDOS, even though they still use it as a Boot system to start a computer with Novell Networking NOS installed. NDOS is not needed after bootup. > Oh, how come only Windows95 can use that area then? I would assume > that > other DOSes would be much more interesting if they could handle it > (I would > change). ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj.