best DOS version

On Wed, 9 Jul 2014, Derrick Meury wrote: An excellent choice. MS-DOS 6.20, 6.21, 6.22 have the unique distinction of being the only versions of DOS for which the primary design goal was to improve reliability, rather than add new "features". By the way, it is NOT 6.2.2, although we tend to use the nomenclature as if it were. There is one "major version", and one "minor version", which is actually a two digit decimal number, between 00 and 99 It is actually, internally, SIX point TWENTY-TWO! If you do a function 3 of the DOS functions: Go into DEBUG.COM, type: A MOV AH,3 INT 21 INT 3 (you must hit enter (to get out of assembly mode)) G You will find that register AX contains 1606, which is 6 in AL for the major version, and 16 (sexadecimal) or twenty-two as the minor version. One thing that I don't like about the later versions, such as 6.22, is that many of the DOS programs, such as DEBUG.COM are actually .EXE files, falsely renamed as .COM (notice the first two bytes of the file are "MZ".) It's generally not a big deal, but it does make it less convenient to modify the contents of the program (using DEBUG) Each version of DOS has many differences from all other versions, but, we tend to only pay attention to the specific differences that we care about. For example, for many years, the only characteristic that really mattered to me was which disk formats it supported. To other people, different things are important. So, feel free to add comments to this list for "what really matters": CP/M What it was intended to replace QDOS "quick and Dirty OS" A place holder, to use for development while waiting for CP/M-86 to be finished SCP-DOS Seattle Computer Products Disk Operating System - "Maybe it'll be a while before CP/M-86 is ready" PC-DOS 1.00 Purchased from Seattle Computer Products, and cleaned/finished a little. First commercial release of Personal Computer Disk Operating System Note that that is a description, NOT a name. it is NOT trademarked, although IBMs lawyers will respond if somebody else tries to trademark it (see DRI) Single sided 8 sector per track (160K) floppies. MS-DOS 1.00 Same as PC-DOS 1.00, except, . . . Sold ONLY to OEMs, NO "legal" retail sales (although massive gray market). IBMBIO.COM and IBMDOS.COM are renamed IO.SYS and MSDOS.SYS. Has GWBASIC ("Gee Whiz"), instead of the ROM dependent BASICA. MODE.COM may differ from the PC-DOS version PC-DOS 1.10 Added DOUBLE sided 8 sector per track floppies (320K) MS-DOS 1.25 Same as PC-DOS 1.10 ("OEMs ONLY" "May only be sold with a new computer") Always look for WHOSE version of MS-DOS! MODE.COM and a few others may have some customization! PC-DOS 2.00 9 sector per track floppies (180K,360K). Hard disks! sub directories, "Unix style" internal DOS file functions (INT21h), in addition to the "CP/M style" file functions. Some talk of making it "unix-like", but IBM insists on '\' instead of '/' as path separator, and defaulting to '/' instead of '-' as switchchar. Addition of function 30h to check DOS version (running a version of CHKDSK MS-DOS 2.00 same as PC-DOS 2.00 PC-DOS 2.10 minor fixes, such as SLOWING the track seek of floppies to work with the [redacted] Qunetrak 142 floppie on the PCJr MS-DOS 2.11 Same as PC-DOS 2.10. Always check for WHOSE MS-DOS! MODE.COM, FORMAT.COM, and numerous other supplied programs (they are NOT "external commands"!) may differ from PC-DOS, and between one and another. Several OEMs add 360K and 720K floppy support, mostly mutually incompatible. PC-DOS 3.00 add 1.2M floppy support (for PC/AT) MS-DOS 3.00 same as PC-DOS 3.00 PC-DOS 3.10 some internal additions, such as network redirector; first version that can handle CD-ROM without major aftermarket add-ons. (CD-ROM is NOT seen as a drive on the computer, it is seen as a drive elsewhere on the network (try doing a CHKDSK of it!)) MS-DOS 3.10 same as PC-DOS 3.10 PC-DOS 3.20 added 720K 3.5" drives, and standardized the format of them MS-DOS 3.20 Same as PC-DOS 3.20. OEMs with 3.5" drives switched to IBMs format. EXCEPT HP. PC-DOS 3.30 Added "1.44M" drives, with 1.40625M capacity. MS-DOS 3.31 Same as PC-DOS 3.31, EXCEPT addition (most? OEMs) of hard drives larger than 32 MB! One of the often heavily customized variants. Always check WHOSE MS-DOS. (Zenith is one of the favorite ones) PC-DOS 4.00 Addition of >32M drive support. Norton fUtilities was not notified in advance to make appropriate changes, so malfunctioned, causing lots of complaints that there was "something wrong with DOS" because Norton fUtilities didn't work. Also, some real bugs, but the most commonly reported ones were because there were changes, that were not supported by Norton fUtilities. PC-DOS 4.01 Bug fixes. New release of Norton fUtilities to handle changes. Some bugs still remain, including function 30h returning wrong DOS version number! MS-DOS 4.01 ? MS-DOS 5.00 First version with LEGAL (not gray market) retail sales. MS-DOS 6.00 Major shopping binge! Lots of third party stuff bundled, including compression, smartdrv, etc. PC-DOS 6.10 Same as MS-DOS 6.10, but compression, etc. bundled stuff SMARTDRV was first bundled with Windoze 3.10, but, in MS-DOS 6.00, it was installed by default. Power lUsers installed compression. SMARTDRV caused data loss, which was inevitable with resequenced and delayed writes if the machine went down (such as the usual practice of hitting the power switch as soon as DOS prompt reappeared after saving the file (which hadn't actually been written yet!) That got blamed on compression! For example, Infoworld "PROVED" that compression caused data loss with a PC with compression (AND SMARTDRV). When Bill Gates told them that their test procedure was bad, and that the problem was not caused by COMPRESSION, they called that attempted intimidation. MS-DOS 6.20 Microsoft repaired the compression! They did that by having SMARTDRV NOT default to rearranged nor delayed writes, and not displaying the DOS prompt until all delayed writes were finished. Many other fixes for reliability. STAC Electronics sued Microsoft over the compression. There had been technology exchange in preparation for a licensing deal that fell through. STAC won ~100 million dollars in their suit. Microsoft won back ~30 million dollars in their counter-suit (technology exchange went both ways. Bill Gates said, "I'm having a bad day." MS-DOS 6.21 Same as 6.20 with NO compression bundled. (in response to the STAC legal vistory) MS-DOS 6.22 Same as 6.20 and 6.21 with a new non-infringing compression bundled. PC-DOS 6.30 similar to MS-DOS 6.20? MS-DOS 7.00 Hidden under Windoze95. PC-DOS 7.10 Similar to MS-DOS 7.00?