------------------------------------------------------------------------------ The Top Ten Most Frequently Asked Questions, (about DM), of All Time: ------------------------------------------------------------------------------ 1. "Why is the DMDRVR.BIN device driver taking up so much of my RAM?" The DMDRVR.BIN device driver only takes up 4.06k of memory. If XBIOS.OVL is loaded for support of disks with more than 1024 cylinders, then the two together take up a total of 6.78k of memory. Invariably, when this question comes up, the person asking it is using DOS 3.x, and has a Disk Manager "write/read" partition that is greater than 32 Meg in size. What is REALLY happening to your RAM is probably this: When you use Disk Manager to create a partition that is greater than 32 Meg in size under a 3.x version of DOS, the logical sector size increases, (under DOS 4.x, the logical sector size remains a consistent 512 bytes no matter how large the partition is, therefore this situation is not a problem under DOS 4.x). The RAM consumption problem arises when the DOS buffer area is allocated. The two factors that determine how large that buffer area is going to actually be are the number of buffers stated in your CONFIG.SYS file, (the number of buffers usually defaults to 8 if there is no BUFFERS= statement in your CONFIG.SYS file at all), and the largest logical sector size that exists in any partition in the system. These two factors are multiplied together to determine how large the buffer area will be. In a "normal" 32 Meg partition, the logical sector size is 512 bytes. Therefore, a BUFFERS=20 setting in your CONFIG.SYS file would create a 10k buffer area, (20*512=10240 bytes=10k bytes). If on the other hand, you have a 50 Meg Disk Manager "write/read" partition on your hard disk, you would end up with a 20k buffer area because the logical sector size has been increased to 1k in order to make the 50 Meg partition possible, (20*1k=20k). The solution to this "bloating" of the buffer area is to decrease the BUFFERS= statement in your CONFIG.SYS file by the same factor, (adjusted upwards to the closest integer), as you have increased the logical sector size by. In this example, since you have doubled the logical sector size, you should cut the number of buffers stated in the BUFFERS= statement in half. A BUFFERS=10 statement would create the same 10k buffer area that you wanted in the first place. When an application program dictates that it wants a BUFFERS=20 statement in the CONFIG.SYS file, all it is really after is a 10k buffer. It is falsely assuming that nobody has anything other than a 512 byte logical sector size. The DOS 3.x partition size vs logical sector size breakpoints are as follows: 0 - 32 Meg = 512 byte logical sector size 32 - 64 Meg = 1k " " " " 64 - 128 Meg = 2k " " " " 128 - 256 Meg = 4k " " " " 256 - 512 Meg = 8k " " " " As you can see from the above table, if you have a 500 Meg partition on your hard disk, and you have a BUFFERS=20 statement in your CONFIG.SYS file, (and you are running a 3.x version of DOS), you would actually be allocating a 160k buffer area!, (20*8k=160k). A BUFFERS=2 statement would be much more reasonable in this situation, giving you a 16k buffer area. ------------------------------------------------------------------------------ 2. "Why can't I have my whole disk as drive C: if I'm using DOS 4.x?" The reason behind why you can't have all of a "nonstandard" disk as drive C: becomes quite clear after you understand what the BIOS ROM and DOS do at boot time, and how Disk Manager comes in later to perform it's magic. Here's a little background on what happens inside of your computer at boot time: In an AT style machine, there is a table of drive types in the ROM BIOS. Each of the entries in this table consist of a drive type number, and an associated set of drive parameters for a particular drive, (number of cylinders, heads, sectors per track, write precompensation cylinder, etc...). The original IBM AT had only twelve entries in this table. There are some machines today that have hundreds of entries in their drive type table. When you "setup" your computer, you have to state what "drive type" number corresponds to the hard disk that you are using, (along with other information about what your computer has in it), and this information is stored in battery backed up CMOS memory. At boot time, the BIOS looks at the drive type number stored in CMOS, and then looks up the corresponding drive table entry in ROM. The parameters for this drive type entry are then placed in a special area of low memory reserved for this function. This is how the system knows what kind of hard disk is installed. This set of parameters are known as the "standard" parameters, because a drive whose parameters are defined in the computer's drive table is a "standard" drive to the system. There are also some hard disk controller cards that have the ability to take control at boot time, before DOS ever comes into the picture, and replace the drive parameters in low memory with a different set of parameters, so that a drive that is attached to that controller may also appear to DOS as a "standard" drive to the system. Disks that are not represented by an entry in the computer's drive table are known as "nonstandard" disks. Since all computer's drive tables are not created equal, a disk that is "standard" to one particular computer may be "nonstandard" to a different brand or model of computer. Disk Manager has the ability to install "nonstandard" hard disks into your computer and allow you to get full access to all of the space on the drive. It does this by writing the actual parameters of the hard disk to an area within the first sector of the disk, (within the Master Boot Record). During the later part of the boot process, after the DOS boot partition, (drive C:), is mounted and running, DOS reads the CONFIG.SYS file and hands over control to the DMDRVR.BIN device driver. DMDRVR goes out to the disk and reads the parameters that DM wrote there at the time of drive installation. Disk Manager "write/read" type partitions can then take advantage of this alternate set of parameters and utilize the area of the disk beyond what is seen by the system as "standard". There's the rub. The DOS boot partition must reside within the "standard" portion of the drive because it needs to be up and running in order for the hidden system files, the CONFIG.SYS file, and the DMDRVR.BIN file to be read from it before Disk Manager is able to come into the picture and tell the system anything different about the disk. Even though Disk Manager does know the true nature of the drive, it still purposely limits the DOS boot partition to reside within the "standard" portion of the drive because it knows it has to in order for DOS alone to be able to understand the boot partition. The second reason that you may not be able to have all of your drive as drive C: is if your drive has more than 1024 cylinders. Since DOS alone cannot see anything above the 1023rd cylinder, the only thing that can reside beyond that point on the drive is a Disk Manager "write/read" partition. ------------------------------------------------------------------------------ 3. "I've got DM 3.x, and have just upgraded to DOS 4.x, now the machine locks up when I try to boot. Why?" People who ask this question have a Disk Manager "write/read" partition that is greater than 32 megabytes that was originally prepared under DOS 3.x. This type of partition has a logical sector size of greater than 512 bytes per sector, as was necessary under DOS 3.x in order to have this size of partition. DOS 4.x rules dictate that all partitions, no matter what size, have 512 bytes per logical sector. So, when you boot up with DOS 4.x, the system assumes that all partitions have 512 byte sector sizes and therefore is confused by this strange partition that has a larger than 512 byte sector size. At this point, the system will rather ungracefully "lock up". The only solution is to boot up with a DOS 3.x floppy that has DMDRVR.BIN on it and a CONFIG.SYS file that has DEVICE=DMDRVR.BIN in it. Once the system is booted, backup the data from the large partition. After you have backed up the data, reboot the system with a DOS 4.x diskette that does NOT have DMDRVR.BIN on it, run DM and re-prepare the large partition. You may then boot the system normally and restore the data back onto the large partition. ------------------------------------------------------------------------------ 4. "How come 60 Meg of data is taking up 80 Meg of space on my disk?" This problem is due to the fact that by default, a DOS "cluster" is 4 times the logical sector size. A "cluster" is the minimum disk space allocation unit on the hard drive. For example: If you have a partition that has a 1024 byte sector size, it will have a 4096 byte cluster size. This means that every file, no matter how small, will take up at least 4096 bytes worth of space on the disk. If the file is 5000 bytes in length, it will take up 8192 bytes of space on the disk, (2*4096=8192). An extreme example is if you have a 500 megabyte partition under DOS 3.x. This size of partition would have a 8k sector size, and therefore a 32k cluster size. In this size of partition, even a 10 byte file would take up 32k of space on the disk. If this situation creates a problem for you, (if you have ample disk space it shouldn't), potential solutions are: A. Make smaller partitions instead. B. Don't put a bunch of tiny little files in your huge partition. Have a smaller partition on the disk as well where you can store these files more efficiently. (One thing to watch out for here: Under DOS 3.x, if you have a partition that is SMALLER than 16 megabytes, it will have a 4k cluster size. Partitions between 16 meg and 32 meg in size are the most efficient and have a 2k cluster size.) C. Use DOS 4.x instead of 3.x. A 500 megabyte partition under DOS 4.x would have a 8k cluster size instead of a 32k cluster size, due to the difference in formatting rules between the two versions of DOS. D. Use the "/V" switch in Disk Manager to manually specify your cluster size when preparing the partition. This option is to be used with extreme caution, since there are many programs that assume that a cluster is ALWAYS 4 times the sector size, starting with CHKDSK. CHKDSK won't understand a partition that does not have a cluster size that is 4 times the sector size and will diagnose it as a "probable non-DOS partition". There are other programs that make the same assumptions, sometimes causing nasty results. The /V switch in Disk Manager is not recommended unless the only thing you are going to do with the affected partition is copy files to and from it with the COPY command for archival purposes, or you know for a fact that your application program will cope with this type of formatting. If you choose to use the /V switch, beware of possible conflicts with other programs, and beyond that you are on your own. ------------------------------------------------------------------------------ 5. "I used DM to install my drive under "Joe's DOS" and it won't boot." When Disk Manager prepares, (high-level formats), a DOS boot partition, it offers to transfer the DOS hidden system boot files to the partition for you. With some versions of DOS, Disk Manager is not able to successfully perform this function. The reason for this is when a company purchases the rights to distribute DOS under their own name, they sometimes also modify the way that the hidden system boot files are placed on the hard disk. Disk Manager is designed to recognize many of these odd versions of DOS, but new ones are coming out all the time. Even straight MS-DOS has been changed from time to time. For example, the layout and size of the hidden boot files changed between DOS v3.2 and DOS v3.3. Disk Manager v3.2 was released prior to DOS v3.3, and therefore couldn't anticipate this change. The end result is that Disk Manager v3.2 cannot successfully transfer the DOS v3.3 hidden system files when it prepares the DOS boot partition. Disk Manager v3.3 was released shortly after DOS v3.3, and was enhanced in order to be able to identify and transfer these files successfully. The workaround for this problem is usually simple. All you need to do is boot up with your DOS floppy diskette, and run the "SYS C:" command to let this version of DOS manually transfer it's own hidden system boot files. If that doesn't work, then try manually formatting the DOS boot partition by issuing the "FORMAT C:/S" command, after which you will have to copy the DMDRVR.BIN and CONFIG.SYS files onto drive C: from your Disk Manager diskette. ------------------------------------------------------------------------------ 6. "I'm using Compaq DOS 3.31 and am only able to copy 15 files to the disk. After that, the file sizes show as being zero bytes." There are some versions of DOS that identify themselves as being 3.x versions, but actually use DOS v4.x rules when they format a hard disk. These hybrid versions of DOS are capable of creating a partition that is greater than 32 megabytes in size all by themselves, unlike normal DOS 3.x. Compaq DOS 3.31 and Zenith DOS 3.3+ both fall into this category. When Disk Manager gets ready to prepare, (high-level format), the partitions on the hard disk, it polls DOS to find out what version it is in order to know what formatting rules to obey. These hybrid versions of DOS will identify themselves as v3.x, so Disk Manager happily proceeds to use v3.x formatting rules, and everything seems to work fine. But, when it comes time to copy files to the disk, the result is that you can only copy 15 files to the disk. (I'm not going to go into why this actually happens. Just treat it as a red flag.) By the way, this is also the same thing that will happen if you try to install DOS v4.x with a copy of Disk Manager v3.x. If you are going to install DOS v4.x, you must have Disk Manager v4.x. The solution to this situation is to use the "/4" switch in Disk Manager, to force it to use DOS v4.x formatting rules. (The "/4" switch is supported by Disk Manager v4.0 and above only, it will be ignored in a 3.x version of Disk Manager since it didn't know what DOS 4.x was). Just run DM/4/M, go to the partitioning menu and re-prepare each partition that is greater than 32 meg in size. If this drive is "standard" to your system, and does not appear to the system as having more than 1024 cylinders, this switch will also allow you to create a large DOS bootable partition that covers the entire drive, (if you are using one of the above versions of DOS). ------------------------------------------------------------------------------ 7. "When I run DIAG.EXE, it says my second drive is 305x4x17. I don't even have a second drive! What is it talking about?" There is a special location in low-memory reserved to hold the parameters, (number of cylinders, heads, sectors per track, etc...), that describe the geometry of your hard disk drives. In the situation where you only have 1 hard drive, the area that is reserved to hold the parameters of the second drive is filled by default with the parameters of CMOS drive type 1, and is then flagged as being "not installed" by the fact that the CMOS drive type is set to 0. When you select the option from with the DIAG program to display all disk parameters, it displays exactly what it finds in these memory locations. It will show you that the second drive is set for drive type 0, (which means "not installed"), but also shows you the actual parameters that are stored in these locations as well. This is a case where the DIAG program is perhaps being a little too honest, and has caused some confusion in the past. If you know you don't have a second physical hard drive, then just ignore this "phantom" set of parameters that show up for drive number 2. A related question is, "I have a drive C: and a drive D:, but DIAG and DM say I only have one drive.". This person has two partitions defined on a single physical hard disk drive. When DM and DIAG talk about hard disk 1 and 2, they are talking about physical hard disk drive units, not partitions. ------------------------------------------------------------------------------ 8. "I used DM to install my drive that has more than 1024 cylinders, and everything seemed to go fine at that time. But now, every time I try to access the area beyond cylinder 1023, I get a "General Failure" error message. How come?" Disk Manager allows you to use a drive with DOS that has more than 1024 cylinders. This is something that DOS is not capable of doing by itself. Older versions of Disk Manager had an external program called SWBIOS.COM that you had to manually run prior to running Disk Manager. Current versions of Disk Manager use an overlay file called XBIOS.OVL for this same function. With these newer versions, XBIOS.OVL gets loaded automatically when you run Disk Manager, so you don't have to remember to do it manually anymore. There are a couple of things that can cause this function to not work: A. The drive is an ESDI or RLL drive, and was low-level formatted through the controller's on board BIOS using debug. The person then ran SWBIOS and then Disk Manager in manual mode and went directly to the partitioning menu to set up his partitions, without first stopping in at the configuration menu to write the parameters of the disk to the Master Boot Record, (MBR), of the hard disk itself. In this situation, everything seems to go fine until an attempt is made to access the area of the disk beyond cylinder 1023, at which point the user gets a "General Failure" error message. This is because if the MBR does not contain the parameters of the disk, DMDRVR assumes that this must be a standard disk to the system, and that the system knows how to handle it all by itself. Therefore in order to avoid a possible conflict with the system's method of going beyond 1024 cylinders, it does not load SWBIOS. Unfortunately, most of the time the system has absolutely no idea how to handle access of the cylinders beyond 1024 by itself, therefore no support for this function gets provided by anyone. The solution to this situation is to boot with DOS, run SWBIOS, run Disk Manager in manual mode, go to the configuration menu, and select W to write the parameters to the disk. From this point on, Disk Manager will realize that the disk has more than 1024 cylinders and that it is in charge of providing support for access of the area of the disk beyond that point, and will get SWBIOS involved. The same scenario holds true for versions of Disk Manager that use XBIOS.OVL. You must still write the parameters to the disk in order for DMDRVR.BIN to realize that the disk has more than 1024 cylinders and therefore needs to load the XBIOS.OVL overlay. This is a good reason to run Disk Manager, (either version), in automatic mode even when low-level formatting the disk through the controller's onboard BIOS. If you have low-level formatted the drive through the controller BIOS in order to make the drive appear as a standard drive to the system, but have not used any translation mode in order to make it appear as though it has less that 1024 cylinders, then just run Disk Manager in automatic mode, and hit ESC to install a standard drive when asked for the drive's model number. This ensures that the parameters of the disk get written to the MBR and that SWBIOS/XBIOS gets loaded properly at boot time. B. The second thing that can go wrong is if you are using a version of Disk Manager that uses XBIOS instead of SWBIOS, the file XBIOS.OVL must reside in the ROOT directory of the boot partition, (C:\). You cannot place it in any subdirectory like you can actual device drivers such as DMDRVR.BIN. If you attempt to place XBIOS.OVL in a subdirectory, DMDRVR.BIN will not be able to find the overlay when it needs it at boot time. ------------------------------------------------------------------------------ 9. "I just installed an application, and after I rebooted I can't get to drive D: anymore. It just says `Invalid Drive Specification'. Where did it go?" What has probably happened here is that you have just installed a rather inconsiderate application that has taken the liberty of rewriting your CONFIG.SYS file in order to change the number of BUFFERS, FILES, or FCBs, or something else that it needs in order to operate. Instead of adding these new lines to the existing CONFIG.SYS file, it has simply replaced the existing one with a new CONFIG.SYS file that does not reference the DMDRVR.BIN Disk Manager partition device driver. The solution for this is to manually add the line DEVICE=DMDRVR.BIN to the new CONFIG.SYS file that the install program has created, and then reboot the computer. When doing this, remember that this line should generally appear as the first line in the CONFIG.SYS file. A second reason that this could happen is that you have erased either the file DMDRVR.BIN or the file CONFIG.SYS from the ROOT directory of your boot partition. The solution for this one is to copy these two files back onto your hard disk from the Disk Manager diskette. ------------------------------------------------------------------------------ 10. "I used Disk Manager to install my hard drive, but now I can't use the "FORMAT D:" command to format my second partition. It says `Format not supported on drive D:' How am I supposed to get it formatted?" That's right. The DOS FORMAT command is not supported on a Disk Manager "write/read" partition, but that's not a problem. A Disk Manager "write/read" type partition must be "prepared" from within Disk Manager. "Preparing" a partition accomplishes the same thing as the DOS FORMAT command does. It performs a "high-level logical format" of the partition. There is absolutely no need to run the FORMAT command on this type of partition. If for some reason you want to completely erase a "write/read" type partition, then you can simply re-prepare it from within Disk Manager. ------------------------------------------------------------------------------