--- layout: page title: Microsoft MS-DOS 4.00 permalink: /disks/pcx86/dos/microsoft/4.00/ redirect_from: - /disks/pc/dos/microsoft/4.00/ machines: - type: pcx86 id: ibm5170-msdos400 config: /devices/pcx86/machine/5170/ega/640kb/rev1/machine.xml autoMount: A: name: MS-DOS 4.00 (Disk 1) path: /disks/pcx86/dos/microsoft/4.00/MSDOS400-DISK1.json --- Microsoft MS-DOS 4.00 --- The PCjs machine below is running PC-DOS 4.00. {% include machine.html id="ibm5170-msdos400" %} MS-DOS 4.00 was released in October 1988. The contents of the six 360Kb distribution diskettes are shown below. ### Directory of MS-DOS 4.00 (Disk 1) Volume in drive A has no label Volume Serial Number is 1456-15F4 Directory of A:\ IO SYS 33321 10-06-88 12:00a MSDOS SYS 37376 10-06-88 12:00a COMMAND COM 37556 10-06-88 12:00a AUTOEXEC BAT 39 10-06-88 12:00a CONFIG SYS 96 10-06-88 12:00a COUNTRY SYS 12806 10-06-88 12:00a DISKCOPY COM 10396 10-06-88 12:00a DISPLAY SYS 15692 10-06-88 12:00a FDISK EXE 60935 10-06-88 12:00a FORMAT COM 22859 10-06-88 12:00a KEYB COM 14727 10-06-88 12:00a KEYBOARD SYS 23328 10-06-88 12:00a REPLACE EXE 19415 10-06-88 12:00a SELECT COM 3642 10-06-88 12:00a SELECT HLP 28695 10-06-88 12:00a SELECT PRT 1329 10-06-88 12:00a SYS COM 11456 10-06-88 12:00a 17 File(s) 18432 bytes free ### Directory of MS-DOS 4.00 (Disk 2) Volume in drive A has no label Volume Serial Number is 2B61-1BE2 Directory of A:\ COMMAND COM 37556 10-06-88 12:00a ASSIGN COM 5753 10-06-88 12:00a ATTRIB EXE 18263 10-06-88 12:00a CHKDSK COM 17787 10-06-88 12:00a COMP COM 9459 10-06-88 12:00a DEBUG COM 21574 10-06-88 12:00a DISKCOMP COM 9857 10-06-88 12:00a EDLIN COM 14069 10-06-88 12:00a FC EXE 15807 10-06-88 12:00a FILESYS EXE 11129 10-06-88 12:00a FIND EXE 5941 10-06-88 12:00a IFSFUNC EXE 21739 10-06-88 12:00a JOIN EXE 17813 10-06-88 12:00a LABEL COM 4458 10-06-88 12:00a MEM EXE 20005 10-06-88 12:00a MORE COM 2134 10-06-88 12:00a SHARE EXE 13424 10-06-88 12:00a SORT EXE 5882 10-06-88 12:00a SUBST EXE 18467 10-06-88 12:00a TREE COM 6302 10-06-88 12:00a XCOPY EXE 17055 10-06-88 12:00a 21 File(s) 56320 bytes free ### Directory of MS-DOS 4.00 (Disk 3) Volume in drive A has no label Volume Serial Number is 2047-15E0 Directory of A:\ COMMAND COM 37556 10-06-88 12:00a EMM386 SYS 87776 10-06-88 12:00a EXE2BIN EXE 7963 10-06-88 12:00a GWBASIC EXE 80608 10-06-88 12:00a LINK EXE 43988 10-06-88 12:00a PRINT COM 14131 10-06-88 12:00a RAMDRIVE SYS 8235 10-06-88 12:00a SMARTDRV SYS 10224 10-06-88 12:00a XMA2EMS SYS 29211 10-06-88 12:00a 9 File(s) 39936 bytes free ### Directory of MS-DOS 4.00 (Disk 4) Volume in drive A has no label Volume Serial Number is 0569-15F3 Directory of A:\ COMMAND COM 37556 10-06-88 12:00a ANSI SYS 9105 10-06-88 12:00a APPEND EXE 11154 10-06-88 12:00a COUNTRY SYS 12806 10-06-88 12:00a DISPLAY SYS 15692 10-06-88 12:00a DRIVER SYS 5241 10-06-88 12:00a FASTOPEN EXE 16702 10-06-88 12:00a GRAFTABL COM 10239 10-06-88 12:00a GRAPHICS COM 16693 10-06-88 12:00a GRAPHICS PRO 9397 10-06-88 12:00a HIMEM SYS 6261 10-06-88 12:00a KEYB COM 14727 10-06-88 12:00a KEYBOARD SYS 23328 10-06-88 12:00a MODE COM 22960 10-06-88 12:00a NLSFUNC EXE 6878 10-06-88 12:00a PRINTER SYS 18914 10-06-88 12:00a RAMDRIVE SYS 8235 10-06-88 12:00a RECOVER COM 10588 10-06-88 12:00a 4201 CPI 6404 10-06-88 12:00a 4208 CPI 720 10-06-88 12:00a 5202 CPI 370 10-06-88 12:00a README TXT 14148 10-12-88 9:13p 22 File(s) 1024 bytes free ### Directory of MS-DOS 4.00 (Disk 5) Volume in drive A has no label Volume Serial Number is 1F41-15E1 Directory of A:\ BACKUP COM 36880 10-06-88 12:00a EGA CPI 49068 10-06-88 12:00a FORMAT COM 22859 10-06-88 12:00a LCD CPI 10703 10-06-88 12:00a MODE COM 22960 10-06-88 12:00a RESTORE COM 36946 10-06-88 12:00a SELECT DAT 22999 10-06-88 12:00a SELECT EXE 95107 10-06-88 12:00a XMA2EMS SYS 29211 10-06-88 12:00a 9 File(s) 30720 bytes free ### Directory of MS-DOS 4.00 (Disk 6) Volume in drive A has no label Volume Serial Number is 1101-1B52 Directory of A:\ CHKDSK COM 17787 10-06-88 12:00a DISKCOPY COM 10396 10-06-88 12:00a PCIBMDRV MOS 263 10-06-88 12:00a PRINT COM 14131 10-06-88 12:00a SHELL CLR 4406 10-06-88 12:00a SHELL HLP 66527 10-06-88 12:00a SHELL MEU 4588 10-06-88 12:00a SHELLB COM 3894 10-06-88 12:00a SHELLC EXE 153855 10-06-88 12:00a DOSUTIL MEU 6660 10-06-88 12:00a COMMAND COM 37556 10-06-88 12:00a 11 File(s) 36864 bytes free --- One important new feature of MS-DOS 4.00 was the ability to update the system files (IO.SYS and MSDOS.SYS) of any boot disk, by moving the first two directory entries (and the contents of the first three data sectors) as needed to make room for the new IO.SYS and MSDOS.SYS files. The SYS command in older versions of MS-DOS would report "No room for system on destination disk" if the first two directory entries (or the first three data sectors) were unavailable. However, after using the MS-DOS 4.00 SYS command, it usually becomes possible to install older MS-DOS versions as well. Learn more about the history of the SYS command from [Microsoft Support](https://support.microsoft.com/en-us/kb/66530). Additional details about MS-DOS 4.00 from [PC DOS Retro](https://sites.google.com/site/pcdosretro/doshist): - distributed on 2 720KB floppy disks [also released on 6 360KB diskettes; the number of 720KB diskettes needs to be verified] - SHARE loaded for FCB operations on hard disks greater than 32MB - IFS driver support added - MEM command added to report memory usage - new internal command: TRUENAME - new external commands: FILESYS, IFSFUNC, MEM - new CONFIG.SYS commands: COMMENT, CPSW, IFS, INSTALL, MULTITRACK, REM, SWITCHES - new device drivers: SMARTDRV.SYS (MS-DOS), XMA2EMS.SYS, XMAEM.SYS - new support file: GRAPHICS.PRO - disk buffers could be allocated in expanded memory (BUFFERS /X) - DPB, SFT and CDS structures extended - new internal version table added - DOS swappable data area changed - program names added to MCBs - INT 21h functions 3305h, 5D0Bh, 5F05h-5F08h, 6507h, 6520h-6523h, 65A0h-65A3h, 69h-6Ch added - INT 21h functions 3303h-3304h, 5702h-5704h reserved but unused - INT 2Fh multiplex function 1Ah (ANSI.SYS) added