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16 BIT OS
16 BIT OS
16 BIT OS

C-Clamp squeezing a man's head
Backup your hard drive


Compressors       Packers   



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Compress What and Why?

PC and XT legacy 80xx computers using 16 Bit software usually have less than 1meg of memory and smaller hard drives than the newer machines. The original IBM PC hard drives were only 10meg drives and many machines had only one floppy drive! The newer XT 80xx machines had 20meg then finally 32meg drives around the same time the 80286's appeared. IBM sold 80286 PS/2's with 20 meg hard drives installed. One double sided 5 1/4 inch 360K floppy was $5 US at this time. No cheap storage anywhere. A solution was in the works.

I do not encourage use of the MSDOS utility DRVSPAC.SYS or any of it's clones to compress an entire partition. With modern Archivers and Packers there is little to gain by compressing an entire partition into one huge file, but you may find yourself with a difficult setup to maintain. Just my opinion, use them at your own discretion.

Archivers

Compression of programs and data files for PC's seemed to begin with the CPM machines but was obviously of interest to all computer users and many compression utilites exist because of this. The original compressors would do one file at a time. A second program did the LIB function to combine the many files into one archive. The older compressors would compress text to half it's original size or less. Eventually many files could be combined into one archive orginally referred to as LIB files then the term archival storage replaced LIB. Newer compressors can reduce text to less than 25% of it's original size. I may eventually list the older compressors under a nostalgia section.

Compressors Making Backups

Making backups using a DOS file compressor is risky. Pkzip, and others, will create volumes (maximum size archive that will store on a floppy disk) but making backups is not the same as attempting to restore a hard drive using them! The real test of any backup software comes much later when you need to restore the files from the backup. Pkzip stores all required data for the disk volumes on the last disk of the set. If this disk is lost or damaged the other disks become useless. Pkzip's poor (almost nonexistent) error recovery becomes a second problem if the backups are stored over too long a period of time. ARJ and RAR will fix errors in their archives and will also create volumes that fit on one floppy but do not put all the necessary keys to the disks on the last disk. RAR's error recovery is a bit better than ARJ but both are good. If you must use a compressor then you should look at the BATCH FILES page here for a good way to do this.

I recommend using backup software after testing the restore function before you need to use the restore.

Packing Executables

At some point the DOS executables began to grow and take up space and special purpose compressors were developed to shrink these DOS programs down to save space on small hard drives and floppies. To compress an executable is referred to as packing the executable to differentiate between the two compressors. The archivers and the packers for executables are not the same types of programs and are not interchangeable.

The software listed on this page are the most often used compressors and packers in use for 16 Bit OS at this time. Other archivers and packers are used but are not as popular with the majority of 16 Bit DOS users.

IF you will be downloading any of this software you really should get a copy of F-Protect first and check for virus (it's free for home use and better than McAfee's). DOS systems aren't under attack in recent years but there may be some virus infected archives left over from the past decade?

Backup your hard drive

  • Archivers
    • RAR v2.50 ©  - Best error recovery and good compression if solid archiving is used. DOS and Windows versions but WinRAR is only for W9x and newer. Self-extracting archive function is included in the one application.

    • ARJ v2.81a ©  - New release v2.81a for DOS 16 BIT. Good compression and decent error recovery. DOS text command line only, no 16 bit Windows version at this time (2002-09-11). Self-extracting archive function is a built in function. ARJ Soft Homepage

    • WINZIP v6.3 SR-1 ©  - Windows v3.x and newer. - No error recovery but can read and uncompress zip, tar, arj, rar, lzh, and many other formats. Creation of archives is ZIP only and requires another separate WINZIPSE application to create self-extracting archives.

    • PKZIP v2.50 DOS ©  - PKZip v2.50 - Fastest compression archiver by far from PKWare (minimal error recovery). DOS and W31 versions available. Creation of self-extracting archives requires a separate application. ( 202k archive ) Note: For blinding speed, PKPAK v3.61 is within 10% of the compression of newer versions but is 50% faster than newer versions, this pre-ZIP archiver also written by Pkware.

    • TAR v3.21 beta  - Tape ARchive utility (C) 1990-97 Tim V.Shaporev. No error-recovery. Slow but good for text files if the gzip compression is used. This non-gnu TAR is especially useful for transferring data between OS's. Allows extract from/write to archives in files, floppies or QIC-02 and ASPI-driven SCSI streamers in both regular and streaming modes.

    • BZIP2-DOS  - Popular with *nix crowd. No obvious advantages over the others? With both DOS and *NIX versions out there transfer of files and data from one OS to the other is a good thing.

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  • Compress EXEcutables
    • APACK - Best. Pack COM and EXE. Technically not a 16 bit DOS utility, apack requires a 386+ with at least 4MB RAM to work with but it is too good to not mention.

    • UPX - Better. Pack COM, EXE and SYS

    • LZEXE - Good but limited to EXE only and all displays are in French. There is a utility included to change COM to EXE for packing.

    • PKLITE © - Good and will pack EXE, COM, and even SYS files. (PKware utility)

    • DIET ©;  - Can be a TSR to pack/unpack files that other utilities cannot. Compresses DATA files, packs EXE, and COM programs and, if loaded as a TSR, automatically unpacks them "On-the-Fly". Similar to using DRVSPAC but without the complexity.

    • XEQ.COM - Not really a packer but an archiver of COM programs (total archive size limited to approximately 60K). XEQ stores those small COM utilities inside of itself to save space on hard drives and floppies. Also helps you to keep them in one place. Very handy application if you like to collect small DOS COM utilities. I pack the COM files and then put them into XEQ to get more into one XEQ file.



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