bose@iuvax.cs.indiana.edu (07/17/89)
I just tried to install a Miniscribe 3085 hard disk on my AST Premium 286. The disk is 85Meg unformatted. I used DiskManager to install the disk. I got 72Megs out of the disk. I set it up to have a .9Meg bootable partition, and a 71Meg read/write partition. I am running Dos 3.3. The problem I am having is that after copying all my files onto the hard disk, 32Megs of files, 52Megs are allocated. I checked how much space is being used by the files, and found that a directory containing 5 entries, totalling 200K was taking up 1.4Meg of disk space. Now I understand that a certain amount of slack is normal, but 20Meg is too much. I am loading a device driver, supplied with DiskManager, to get the large partition size. I have also tried it with Dos 4.1 and don't have a problem with slack, however, I get only 62Megs from the disk. Has anyone had the same results or know what is the fix?
karl@ddsw1.MCS.COM (Karl Denninger) (07/18/89)
>Item 4368 (0 responses) by bose at iuvax.cs.indiana.edu on Mon 17 Jul 89 14:17 >[<No Identification>] Subject: Miniscribe 3085 on Dos3.3? > > >I just tried to install a Miniscribe 3085 hard disk on my AST Premium 286. >The disk is 85Meg unformatted. I used DiskManager to install the disk. I >got 72Megs out of the disk. I set it up to have a .9Meg bootable partition, >and a 71Meg read/write partition. I am running Dos 3.3. > >The problem I am having is that after copying all my files onto the hard >disk, 32Megs of files, 52Megs are allocated. I checked how much space is ...... You're in trouble. The reason for the large usage of space is that each file is taking up much more space than would otherwise be consumed. I believe that you are using 8K per file -- regardless of the amount of storage actually _used_. We have seen this as well, and it is a limitation of MSDOS. You can't have large partitions and not run into this. For this reason, we recommend most users partition their drive into multiple <= 32MB pieces. Then you end up with 2K allocation units, and for most users, much more free disk space. Dos 4.1 uses a larger bit table for the FAT, and thus can deal with larger disks without changing the allocation size. This is a help -- but the first time you run one of those utility programs that doesn't know what DOS 4 is, it will SCRAMBLE BEYOND REPAIR your FAT tables! Be careful with this! I would use Dos 3.3 and partition for smaller "chunks" unless you have a compelling need to have more than 32Mb in a single file or directory. -- Karl Denninger (karl@ddsw1.MCS.COM, <well-connected>!ddsw1!karl) Public Access Data Line: [+1 312 566-8911], Voice: [+1 312 566-8910] Macro Computer Solutions, Inc. "Quality Solutions at a Fair Price"
andyross@ddsw1.MCS.COM (Andrew Rossmann) (07/18/89)
> Resp: 1 of 1 by karl at ddsw1.MCS.COM >Author: [Karl Denninger] >... >Dos 4.1 uses a larger bit table for the FAT, and thus can deal with larger >disks without changing the allocation size... This is not true. DOS 4, when using partitions >32M still uses the same 16-bit FAT it uses under DOS 3.x. The difference is in the INT 25h and INT 26h functions. Originally, you could only enter a sector number between 0 and 65535 (0000 - FFFF). Since sectors are usually 512 bytes, 65536*512 bytes = 33554432 bytes = 32M. DOS 4 (and Compaq DOS 3.31) supports an alternative entry method that uses 32-bit sector numbers. DOS 4 will support up to 128M using 2K clusters. It will start increasing the cluster size as you go over 128M. The cluster size can hit 64K!! Under DOS 4, you can use the 'standard' INT 25/26h method for accessing disks/partitions < 32M. If your paritition is >32M, you MUST use the alternate method. For those interested, the alternate metod is: INT 25H is disk read, INT 26H is disk write: AL=drive number (A=0, B=1...) if <32M then CX=number of sectors to read, DX= starting sector, and DS:BX is the buffer where the data is/should go. if >32M then CX=-1 (FFFFh), DS:BX point to a parameter block: bytes 0-3 are a 32-bit sector number (low, low-mid, hi-mid, hi) bytes 4-5 are number of sectors to read bytes 6-7 are offset of buffer bytes 8-9 are segment of buffer The 'old' method can only be used if a disk partition is <32M. The 'new' method can be used on ANY disk. andyross@ddsw1.MCS.COM
andyross@ddsw1.MCS.COM (Andrew Rossmann) (07/18/89)
Forgot to add some additional info about DOS 4. Several UNDOCUMENTED DOS calls have had some changes. The most annoying is function 1Fh, Get default DOS parameter block and 32h, Get DOS Parameter Block. Apparantly, the number of sectors for FAT entry is now a WORD instead of a BYTE. This has pushed the directory sector #, Device header address, Media descritor (!!), and other info up 1 byte. If you have a program that tells you that your media descriptor is 0, then it is using one of these functions. Also, Function 52h, Get Disk List, has also changed. Most especially, the data pointed to at offset 16h has changed, and is larger. andyross@ddsw1.MCS.COM
Ralf.Brown@B.GP.CS.CMU.EDU (07/18/89)
In article <[4368.3]comp.ibmpc;1@ddsw1.MCS.COM>, andyross@ddsw1.MCS.COM (Andrew Rossmann) wrote: } Forgot to add some additional info about DOS 4. Several UNDOCUMENTED DOS }calls have had some changes. The most annoying is function 1Fh, Get default }DOS parameter block and 32h, Get DOS Parameter Block. Apparantly, the }number of sectors for FAT entry is now a WORD instead of a BYTE. This has Not surprisingly, since FAT's may now be up to 256 sectors long.... Besides, on undocumented functions you HAVE to expect change. Particularly when you consider that even documented functions have changed between versions (DOS 2.x and 3.x "get country-dependent info" are quite different, and incompatible). -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=-=- Voice: (412) 268-3053 (school) ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: Ralf Brown 1:129/46 FAX: available on request Disclaimer? I claimed something? PROGRAM n. A magic spell cast over a computer allowing it to turn one's input into error messages. tr.v. To engage in a pastime similar to banging one's head against a wall, but with fewer opportunies for reward. -- from a flyer advertising for _Inside_Turbo_Pascal_
karl@ddsw1.MCS.COM (Karl Denninger) (07/19/89)
>Response 2 of 3 (4368) by andyross at ddsw1.MCS.COM on Mon 17 Jul 89 17:55 >[Andrew Rossmann] > >> Resp: 1 of 1 by karl at ddsw1.MCS.COM >>Author: [Karl Denninger] >>... >>Dos 4.1 uses a larger bit table for the FAT, and thus can deal with larger >>disks without changing the allocation size... > > This is not true. DOS 4, when using partitions >32M still uses the >same 16-bit FAT it uses under DOS 3.x. .... >0 and 65535 (0000 - FFFF). Since sectors are usually 512 bytes, >65536*512 bytes = 33554432 bytes = 32M. DOS 4 (and Compaq DOS 3.31) >supports an alternative entry method that uses 32-bit sector numbers. DOS 4 ... But Andy, that is what I said! The FAT is _larger_ (at least for big partitions it is). >DOS parameter block and 32h, Get DOS Parameter Block. Apparantly, the >number of sectors for FAT entry is now a WORD instead of a BYTE. This has As in the FAT is (or may not be, depending on disk drive size) not the same size as it was before....... Run utilities that don't know the difference on a large DOS4 partition, and watch your FAT (and probably root directory) get munched. I've seen it happen, and it's not pretty. This is one of the reasons we don't encourage the use of DOS4. While the direct large partition support is nice, it's not guaranteed to be compatible with all the utility software out there. And I _hate_ having to pick up the pieces when a customer gets hosed by some software that is supposed to "optimize" his or her disk drive, etc... -- Karl Denninger (karl@ddsw1.MCS.COM, <well-connected>!ddsw1!karl) Public Access Data Line: [+1 312 566-8911], Voice: [+1 312 566-8910] Macro Computer Solutions, Inc. "Quality Solutions at a Fair Price"
jason@cadnetix.COM (CDX Generic User) (07/20/89)
If anyone has had any experience with the Seiko CM1430 monitor, I'd love to hear about it. Thanks, Jason
wek@point.UUCP (Bill Kuykendall) (07/20/89)
We've standardized on Compaq DOS 3.31. Your allocation block size on a disk with 70-80 megs formatted will be 4k, which is quite acceptable. Compaq 3.31 will not have the memory headaches or incompatibility problems you find with 4.0, but there *are* a few (very few) utilities that will not work correctly because they twiddle the FAT directly. Norton's utilities were the worst about doing that, but a new release has solved that problem. I certainly wouldn't choose my operating system based on the few maverick programmers who refuse to follow the rules. In fact, we switched to PCTOOLS when Norton was still having problems and never went back. PCTOOLS is better. If the good ole public domain NSWP (transplanted from the CP/M world!) can handle the new file systems, you gotta wonder about "professional" packages that can't! [ For those of you about to flame me about the depth of Norton's capabilities, I suggest that A) you check out PCTOOLS and B) explain why Norton's new stuff works if the old approach was really necessary ] Bill Kuykendall ...ddsw1!point!wek