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Text File | 1986-06-18 | 9.2 KB | 214 lines

SST - THE SEEK STOPPER Copyright 1986 Alfred J. Heyman Version 2.00 Feel free to copy and share SST with others so long as it is distributed in its unmodified form and as long as no disk copy or duplication fee is charged. The Author reserves the sole right to distribute SST for profit. If you find SST to be useful, And/Or would like to be notified about getting possible future SST enhancements, you can become a registered SST user by Sending $10 to the Author at the Address below. Alfred J. Heyman Room 101 P.O. Box 172101 Memphis, TN 38187 SST may not be used in a commercial environment without the above mentioned registration. Source code is available. ---------------------------------------------------------- WHAT IS SST? SST is a program that is designed to reorganize a DOS disk so that it will run "Faster". Normal daily use of a disk will produce a disk with many fragmented files and subdirectories. Simply put, these are files that are not completely contiguous or together, but are spread out all over the disk. These fragmented files and subdirectories slow disk access down because DOS must tell the Disk Head to Seek to other parts of the disk to pick up other parts of the same file. For example, your disk might have three files on it that we will call A,B,and C. Different parts might be arranged as follows.... AAAAAAABBBBBBBBAAAC CCAAABBBB CCC SST would reorganize the three files so that all of their parts would be contiguous.... AAAAAAAAAAAAABBBBBBBBBBBBCCCCCC This change would shorten the amount of time that it takes DOS to read in the file. If a subdirectory is fragmented, fixing it will speed up disk access time even more noticeably! __________________________________________________________ Syntax: SST [d:] [ TEST] [ CLEAR] TEST - will run SST in a READ-ONLY mode. No alterations will be made to the disk. CLEAR - will Clear move all erased entries in all directories to the ends of those directories. __________________________________________________________ SO WHATS SO GREAT ABOUT SST? The main difference between SST and other Disk Optimizing programs is the way that SST achieves the end result. SST was designed to be FAST. SST is also NOT copy-protected and never will be. SST reads in all of the data that it will need during the run session and Keeps this information in memory. Specifically, SST uses DOS Interrupts 25h and 26h to look at the boot track and other parts of the disk. Information about the disks' characteristics are stored there. SST makes a quick comparison of the data it gets here with what DOS thinks about the disk. If these two sets of data agree with each other, SST will read in the disks File Allocation Table, Root Directory and All subdirectories. ALL of this information is kept in memory during the SST session. SST then decides on the best way to reorganize the disk's clusters. When this is finished, the user is prompted (Y or N) to continue or not. A "Y" response to the above question will start the File Cluster Swapping procedure. Here, the actual file data is physically moved. All data is buffered IN MEMORY. When SST is finished SWAPPING, it then updates the File Allocation table on the disk, and all directories. Some disk optimization programs use the slower and safer method of buffering file data to the disk. While this practically eliminates the chances of data losses because of accidents such as power failures, it makes the program run incredibly slow on a nearly full disk. SST DISADVANTAGES: WARNING: It is strongly advised that the user back up his disk before using SST. Since SST buffers all Data, Tables, and Directories to Memory, IF A POWER FAILURE OCCURS WHILE CLUSTER SWAPPING IS IN ACTION... ALL DATA WILL BE LOST. The Same thing goes for ANY interruption during the SWAP procedure. Simply LEAVE SST alone after pressing "Y" when prompted! SST assumes that all disk sectors that are bad are so marked in the File Allocation Table. If you have a Hard disk that causes you problems... I.E. it develops unexpected bad Sectors regularly, Don't use SST on it unless you have verified that the disk is currently OK. One way of doing this is with Peter Norton's DiskTest Program in his Norton Utilities Package. (CopyRight Peter Norton). THE SST USER: SST is intended for Computer users who have the ability to quickly back up their disk and who don't have the time to waste for a simple disk optimization. Other disk optimizers can take many hours to work on a LARGE/FULL disk. SST can usually handle these more quickly. For Example, SST has reorganized a 32 MEG Hard disk on an AT compatible in under 30 minutes. This particular Optimization moved over 20 Meg of data. Zero Bytes were free on the disk. SST LIMITATIONS: SST is designed to run only in a single user, non-multi- tasking system without stay resident programs installed. SST can perform an optimization on almost any standard DOS disk up to 32 Megabytes in size as long as sectors are 512 bytes long. However, it should be noted that SST needs a lot of memory to work with Bigger disks. If SST runs out of memory, a runtime error FF will halt the program. This error typically occurs while SST is reading in the Subdirectories and before anything is moved or changed on the disk. SST's Memory allocation routines will look to see if enough memory is available when the "BIG BYTES" are needed. A lack of memory returns a message along with the Runtime Error FF message. The Smaller Dynamic Memory allocations are not PreChecked. These routines are called many times... (Thousands of times on Hard disks) and it would slow things up a great deal to do a bunch of calculations every time that 16 bytes were needed, especially since SST's Library Routines AUTOMATICALLY check on Stack/Heap memory availability in order to generate this Runtime Error. If SST just can't quite make it to the SWAPPING procedure with the memory that you have, you can do a few things to try and get it to run. Simply do a cold boot without any unneeded device drivers like ANSI.SYS in the system. Temporarily rename your CONFIG.SYS file to something else and boot up without any of the other DOS parameters that you may specify that eat up memory (BUFFERS=##). SST does not use Dos' DISK buffers to move any disk cluster data. Don't run ANY Stay Resident programs before SST. The extra 1 or 2K of free memory gained with these methods has proven to be enough before! MEMORY USAGE SPELLED OUT: SST uses 16 bytes of memory for every used cluster on the disk. This translates to 262k for a completely full 32Meg Hard disk. SST uses 32 bytes of memory for every active directory entry on the disk. One thousand files would use up 32000 bytes of RAM. SST will buffer out one complete copy of the File allocation Table. This would use up another 32K of ram on a 32Meg Hard Drive. The program also needs another 64k for dynamic variables when run on a 32Meg drive..... As you can see, this all adds up very quickly. If you plan to run SST on a 32Meg drive, you will need at LEAST 512K, If you have 640K, you should not have memory problems with SST and a 32 Meg Drive. For smaller drives such as 20 Meg and 10 Meg, The memory requirements are much lower. __________________________________________________________ * DISCLAIMER * The author makes no claims or guarantees about the use misuse, or suitability of SST on a particular computer. It is the users duty to take adequate precautions to prevent and recover from any accidental data loss because of power failure or any other cause.