Formatting With High Capacity I. Introduction How many times have you transferred a series of files to a floppy diskette, only to find that you were some 5 or 10KB short of space? How many times have you had to back up 10MB of files from your hard disk to 360KB floppies (because you didn't want to pay up to $3.50 per disk, or perhaps because you didn't have a high capacity drive), and sat in front of your computer for 30 minutes or more, switching 3 boxes of floppies in and out of the drive, flipping the door open, flipping it shut, ad nauseam? Then you had to sit there for another 30 minutes or so, transferring files from your hard disk to floppies, changing diskettes every 30 seconds or so (depending on the speed of your machine), or sat there waiting (and still having to switch diskettes in and out) while your backup program did it 'automatically'. And if you had 20, or 40, or 60MB, the formatting and backup times would be doubled, quadrupled, even sextupled. Finally you took the plunge and bought that high capacity drive, and found that you could buy high density disks for as little as 50 cents each, without labels and with envelopes into which you had to squeeze them. But never mind. Now you could back up your 10MB onto only 8 or 9 floppies. So instead of paying $9 for 30 standard density floppies, you paid $5 for 10 high density disks (which you bought in bulk, 50-100 or more). You start formatting a box of high density floppies, and find that, instead of the 40 seconds it took for the 360K disks, the 1.2MB take about 85 seconds. So you've already cut your formatting time for backing up 10MB from 30 minutes to only 13 minutes! Now you only have to switch one-third as many diskettes while backing up your hard disk. Your spreadsheet files have grown from 30KB to over 200KB. Your Word DOC files are rapidly approaching 500KB. You find that you can barely squeeze 6 spreadsheets or 2 DOC files onto the high density disks. You find that when you back up your disks, little files like EXCEL.EXE (599,808 bytes) take up half a disk, while your 6 spreadsheets and their accompanying graphs now occupy nearly 700KB. You'll have to put the worksheets on one disk, and back up the program files onto another. You find yourself formatting more disks. There must be some shorter way, some way to get more mileage, more storage capacity out of the diskettes, either standard or high density. Or maybe there are faster ways to format the diskettes. There are. You run across a program called Format Master, which formats 360KB disks in about the same time it takes the DOS Format command to do it. But lo and behold! There is a switch in Format Master that lets you format 360KB diskettes to 400KB in your standard density drive, using 10 sectors per each of 40 tracks instead of 9. So you can get 11% more bytes on each disk. You now only need 25 diskettes to back up 10MB. You have saved 2 diskettes per 10MB. And you don't encounter the "disk full" message so often! What to do with programs like Excel? Of course you can always put them back on your hard disk from the original program disks. But this usually requires you to reinstall the entire program. It would be much easier if you could back up your program files to diskettes, and then just put them back into their appropriate directories. How do you get the extra storage space on high density diskettes? You look around at other freeware, shareware, or commercial formatting programs. You find one called 720FMT, but it only formats 360KB diskettes to 720KB, and you can already format them to 800KB. Besides, it requires the line DEVICE=DRIVER.SYS in your CONFIG.SYS file, which gobbles up additional RAM. And to complicate things even further, it is memory-resident, eating up more of your precious RAM. You run across a program called 800KFMAT. But you can already get this capacity from Format Master. Besides that, 800KB diskettes formatted with 800KFMAT sometimes cannot be read properly in the standard density drive, and moreover cannot be written to or copied from. You also find that the FormatMaster program mentioned above will perform the same format with the 800K switch on, and with the 360KB disk in the A: drive. You find a program called 800 II, which will format 360KB diskettes to either 360 or 400KB in a standard drive, and to 720 or 800 in a high density drive. It will also format high density diskettes to either 1200 or 1369KB in a high density drive. This program uses the DOS syntax parameters described below. You find that with the program FORDSK you can decrease the normal number of directory entries from 112, occupying 7 sectors or 3584 bytes, to as few as 2 or 512 bytes, saving over 3KB. You also note that you can format 42 tracks instead of 40. When you run CHKDSK on a diskette formatted with these parameters, you find 384,000 bytes usable, instead of 362,496, or an increase of 21,504 bytes per disk. The program MAXI154a lets you format 360KB diskettes to 420KB, and 1200KB diskettes to 1275KB, both in high density drives. Some difficulty may be experienced in reading to and writing from these disks. The small resident program SMAX.COM is provided to facilitate read-writes. II. DOS Formatting Techniques We are all familiar with the MS-DOS or PC-DOS manuals, in their various versions and editions. We all deplore the often incredible omissions of information in these various manuals. My particular version for MS-DOS 3.2 provides the syntax for FORMAT as FORMAT [/1][/4][/8][/b][/n:][/t:] [/v][/s] The drive must be specified as a letter, so that DOS can interpret whether the drive is soft or hard, standard or high density, so that it can set the default parameters. The switch /1 lets you format a disk on one side only (I can't think why!) The switch /4 lets you format a standard density (360KB) diskette in a high density drive, usually the A: drive. The manual warns that some drives cannot read disks formatted in this manner reliably. I have never had this problem. Since it gets to be a matter of habit of using the A: drive, my formatting programs, i.e., batch files, specify the /4 switch for 360KB disks. The /8 switch lets you format either 360 or 1200KB diskettes with only 8 tracks per side. Again, I don't know why anyone would use this switch. In both instances you end up with 322,560KB of usable space. The program ANADISK recognizes a 1200KB disk formatted in this manner as a low-density disk with 40 tracks and 8 sectors per track, the same as the 360KB disk. The 1200KB disk, moreover, cannot be read in the standard density drive. The /b switch is the same as the /8 switch, but adds the system files to either size disk when it is finished formatting. I cannot understand the rationale for either one of these switches. The T and N switches can be used to specify the number of tracks and of sectors per track, other than the DOS defaults. Unfortunately, the manual does not tell you what the defaults are, nor the ranges allowed for either parameter. It always strikes me as strange that writers of manuals assume that their readers know either nothing or everything. III. Formatting Standard or Low Density Diskettes The defaults for formatting a standard density (360KB) diskette in the (usually) B: drive are FORMAT B: /T:40 /N:9 The space between the two parameters is not necessary, and T and N can be upper or lower case. If you enter the command FORMAT B: /T:44 you will get the message "invalid parameter". Any value for T above 43 will result in this message. If you enter FORMAT B: /T:43 formatting will continue, and you will get a disk formatted with 43 tracks, 9 sectors per track, and usable space of 390,144 bytes. This is equivalent to a 387KB disk, an increase of 7.5%. If you add to the command above FORMAT B: /T:43 /N:10 you will get a disk with 434,176 bytes, equivalent to a 430KB diskette. This increases the usable capacity by nearly 20%. I have no difficulty in reading and writing to them in either of my Panasonic high and low density drives. At the end of the formatting there will usually be a slight click, as the heads try to reach for the last two tracks. This does not present any problem so far. IV. Formatting High Density Diskettes The defaults for formatting a high density disk are FORMAT A: /T:80 /N:15 resulting in a disk with 1,213,952 usable bytes. If you enter the command FORMAT A: /T:85 /N:17 you get a disk formatted to the equivalent of 1363KB, with 1,410,560 bytes usable. This is an increase in usable capacity of over 16%. I have tested these disks in various ways, copying and moving large files (up to 600KB) to and from them, and I have had no difficulty whatsoever. The limiting T and N parameters for 360KB disks in a low density drive are 43 tracks and 10 sectors per track. The corresponding limits for high density disks formatted in a high density drive are 85 tracks and 17 sectors per track. I am quite certain that both IBM and Microsoft are aware of this. If they are not, they should be. They are also described in the 800 II program mentioned above. V. The Ultimate Low Density Formatted Disk As I pointed out above, at least two programs, Format Master and 800KFMAT, will format standard density disks to 800KB, providing 812,032 usable bytes per disk. This is an increase of over 124% when compared to the usual 362,496 bytes for a standard 360KB format. This brings the cost of storage down to practically nothing! That box of standard floppies that used to hold 35,400 KB now provides an additional 43,900KB of storage space! Instead of paying $.80 per KB, you now pay only $.36. When you need some place to store or back up that 600KB file or program, you have it, and you don't have to worry about the "disk full" message. Enough? Well, almost. This happened quite by accident. I had some 335 files stored on a standard density disk formatted to 800KB. When I tried to read the directory of the disk (in the A: drive, of course) using Norton Commander (which is my standard DOS shell), I got mostly garbage. Some of the files had disappeared completely. I tried to recover them with Norton's Unerase utility, but they just weren't there. I then used the Norton Disk Doctor to analyse the diskette. I was told that the boot record and FATs were corrupted. After fixing these, the files were still unavailable. I went back into Norton Disk Doctor and selected "Revive a defective diskette." I was asked which drive, and selected A:. I was then asked the size of the disk, and selected 1200KB. I had tried this procedure with a corrupted disk previously, and selected 360KB, since this was the "original" size of the diskette. When Norton Disk Doctor got through "reviving" that disk, it was hash! After selecting the A: drive and 1200KB, I let Norton "revive" the diskette. This takes about 30 minutes, since the revival of each successive cylinder takes longer than that of the previous one. When the Disk Doctor had finished, I ran a free space check on the disk (I usually use Veal's GFS program, fast and uncluttered). To my surprise the free space was 1,213,952 bytes! The Disk Doctor, recognizing the original 800KB format and thinking that this was a high density disk, had reformatted the entire disk with 80 tracks and 15 sectors per track. Wondering whether this was simply an error in the Disk Doctor program, I tried it again with a normally formatted 360KB disk. The result was a 360KB disk. I then formatted the 360KB disk to 800KB, and ran it through the Disk Doctor. Again, 1,213,952 bytes! The results are reproducible. (For the curious, yes, of course I lost all of the files! And yes, this *was* the backup diskette!) The entire formatting takes about 30 minutes. That leaves it up to you, as to whether you have the time, and whether that time is worth the amount of money saved. If you are paying $2.95 per 10 standard diskettes and getting 3540KB, you could be getting 11,855, or an additional 8315KB per box. Taking into consideration the cheapest disks, .e.g., $.29 and $.49 each for standard and high density diskettes, this technique can lower your cost per megabyte by 50%, from about $.81 to $.41. Aside from any monetary considerations, you can now store the same amount of data in less than 30% of the former space. Comments and criticisms (gently, please!) are welcome. This work was done on an AT 286 10MHz clone, with two Panasonic floppy diskette drives, a Miniscribe 6085 68MB (formatted) hard drive, and 1MB RAM. The DOS version is PC-DOS 3.3. Dr. H. S. Friedman [72261,474] Please send comments, etc., via EasyPlex.