Misplaced Pages

DOS API: Difference between revisions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively← Previous editContent deleted Content addedVisualWikitext
Revision as of 21:16, 22 June 2012 editAsmpgmr (talk | contribs)920 edits →References: add The MS-DOS Encyclopedia← Previous edit Latest revision as of 19:18, 19 November 2024 edit undoInternetArchiveBot (talk | contribs)Bots, Pending changes reviewers5,387,806 edits Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0.9.5) (Whoop whoop pull up - 21816 
(89 intermediate revisions by 40 users not shown)
Line 1: Line 1:
{{Short description|API of the MS-DOS operating system}}
⚫ The '''MS-DOS API''' is an ] used originally in ]/], and later by other ]<!--disambiguate--> systems. Most calls to the DOS API invoke ] 21h (] 21h). By calling INT 21h with a subfunction number in the AH ] and other parameters in other registers, one invokes various DOS services. DOS services include keyboard input, video output, disk file access, executing programs, memory allocation, and various other things. The subfunctions provided in the first release of MS-DOS in 1981 were strongly oriented to compatibility with ]. A major revamp of the DOS API (partially influenced by certain Unix concepts) was undertaken for the release of MS-DOS 2.0 in 1983, adding numerous new subfunctions to deal with file I/O using abstract "handles" and support for subdirectories. In these new subfunctions, strings are usually terminated by a NUL byte (]). In MS-DOS version 3.1 (released in 1985), several subfunctions were added for dealing with networks.
{{more footnotes|date=May 2015}}
{{Use dmy dates|date=May 2019|cs1-dates=y}}
⚫ The '''DOS API''' is an ] which originated with ] and is used in ]/] and other ]-compatible operating systems. Most calls to the DOS API are invoked using ] 21h (] 21h). By calling INT 21h with a subfunction number in the AH ] and other parameters in other registers, various DOS services can be invoked. These include handling keyboard input, video output, disk file access, program execution, memory allocation, and various other activities. In the late 1980s, ]s along with the ] (DPMI) allow the programs to run in either 16-bit or 32-bit protected mode and still have access to the DOS API.


==History of the DOS API==
There are various implementations of the DOS API, including ], ], ], ], ], and others.
The original DOS API in 86-DOS and MS-DOS 1.0 was designed to be functionally compatible with ]. Files were accessed using ]s (FCBs). The DOS API was greatly extended in MS-DOS 2.0 with several ] concepts, including file access using ], ] and device I/O control.<ref>{{cite book |title=Advanced MS-DOS Programming: The Microsoft Guide for Assembly Language and C Programmers |author=Ray Duncan |publisher=Microsoft Press |year=1988 |isbn=0914845772 |url-access=registration |url=https://archive.org/details/advancedmsdosmic00dunc }}</ref> In DOS 3.1, ] support was added. In MS-DOS 3.31, the INT 25h/26h functions were enhanced to support hard disks greater than 32 MB. MS-DOS 5 added support for using ] (UMBs). After MS-DOS 5, the DOS API was unchanged for the successive standalone releases of DOS.


⚫ ==The DOS API and Windows==
]s along with the ] (DPMI) extend the DOS API to either 16-bit or 32-bit protected mode.
In ], DOS loaded the protected-mode system and graphical shell. DOS was usually accessed from a ] (VDM) but it was also possible to boot directly to real mode ] without loading Windows. The DOS API was extended with enhanced internationalization support and ] support, though the long filename support was only available in a VDM. With ] OSR2, DOS was updated to 7.1, which added ] support, and functions were added to the DOS API to support this. ] and ] also implement the MS-DOS 7.1 API, though Windows ME reports itself as MS-DOS 8.0.


⚫ ] and the systems based on it (e.g. ] and ]) are not based on MS-DOS, but use a ], ], to handle the DOS API. NTVDM works by running a DOS program in ] (an emulation of ] within ] available on ] and higher processors). NTVDM supports the DOS 5.0 API. ] for ] uses a similar approach.
⚫ ==The MS-DOS API and Windows==


⚫ ==Interrupt vectors used by DOS==
] versions 1.0 through 3.1 were graphical shells that ran on MS-DOS and relied on the MS-DOS API (though using ] for ''Windows'' programs). ] was also DOS-based, but used a custom version of MS-DOS, mainly as a ]. It did not use the MS-DOS API much after booting. However, Windows 9x provided the DOS API to programs running within a command shell window. Earlier Windows 9x versions (at least through the first edition of Windows 98) also can be booted into plain ] "DOS mode" with no GUI and no Windows system services, for running pure DOS programs. The Windows 9x DOS versions (numbered 7.0 and above) include several new service subfunctions for dealing with long filenames (]s).
The following is the list of interrupt vectors used by programs to invoke the DOS API functions.


⚫ ] and the systems based on it (e.g. ] and ]) are not based on MS-DOS, but use a ], ], to handle the DOS API. NTVDM works by running a DOS program in ] (an emulation of ] within ] available on ] and higher processors). ] for ] uses a similar approach.

⚫ ==Interrupt vectors used by DOS==
{| class="wikitable" border="1" {| class="wikitable" border="1"
|- |-
Line 17: Line 20:
!Description !Description
!Version !Version
!Notes
|- |-
|{{Code|20h}} |{{Code|20h}}
|Terminate program |Terminate program
|1.0+ |1.0+
|Implemented in DOS kernel
|- |-
|{{Code|21h}} |{{Code|21h}}
|Main DOS API |Main DOS API
|1.0+ |1.0+
|Implemented in DOS kernel
|- |-
|{{Code|22h}} |{{Code|22h}}
|Program terminate address |Program terminate address
|1.0+ |1.0+
|Return address in calling program
|- |-
|{{Code|23h}} |{{Code|23h}}
|Control-C handler address |Control-C handler address
|1.0+ |1.0+
|Default handler is in the command shell (usually COMMAND.COM)
|- |-
|{{Code|24h}} |{{Code|24h}}
|Critical error handler address |Critical error handler address
|1.0+ |1.0+
|Default handler is in the command shell (usually COMMAND.COM)
|- |-
|{{Code|25h}} |{{Code|25h}}
|Absolute disk read |Absolute disk read
|1.0+ |1.0+
|Implemented in DOS kernel, enhanced in DOS 3.31 to support up to 2 GB partitions
|- |-
|{{Code|26h}} |{{Code|26h}}
|Absolute disk write |Absolute disk write
|1.0+ |1.0+
|Implemented in DOS kernel, enhanced in DOS 3.31 to support up to 2 GB partitions
|- |-
|{{Code|27h}} |{{Code|27h}}
|Terminate and stay resident |Terminate and stay resident
|1.0+ |1.0+
|Implemented in COMMAND.COM in DOS 1.0, DOS kernel in DOS 2.0+
|- |-
|{{Code|28h}} |{{Code|28h}}
|Idle callout |Idle callout
|2.0+ |2.0+
|Called by DOS kernel when waiting for input
|- |-
|{{Code|29h}} |{{Code|29h}}
|Fast console output |Fast console output
|2.0+ |2.0+
|Implemented by the built-in console device driver or a replacement driver like ANSI.SYS
|- |-
|{{Code|2Ah}} |{{Code|2Ah}}
|Networking and critical section |Networking and critical section
|3.0+ |3.0+
|Called by DOS kernel to interface with networking software
|- |-
|{{Code|2Bh}} |{{Code|2Bh}}
|Unused |Unused
|
| |
|- |-
|{{Code|2Ch}} |{{Code|2Ch}}
|Unused |Unused
|
| |
|- |-
|{{Code|2Dh}} |{{Code|2Dh}}
|Unused |Unused
|
| |
|- |-
|{{Code|2Eh}} |{{Code|2Eh}}
|Reload transient (COMMAND.COM) |Reload transient
|2.0+ |2.0+
|Implemented in COMMAND.COM
|- |-
|{{Code|2Fh}} |{{Code|2Fh}}
|Multiplex |Multiplex
|3.0+ |3.0+
|Implemented in DOS kernel and various programs (PRINT, MSCDEX, DOSKEY, APPEND, etc.) depending on subfunction number
|} |}


==DOS INT 21h services== ==DOS INT 21h services==
The following is the list of functions provided via the DOS API primary software interrupt vector.
⚫ {| class="wikitable" border="1" style="margin-left:1em"

⚫ {| class="wikitable" border="1"
|- |-
!{{Code|AH}} !{{Code|AH}}
Line 527: Line 549:
|} |}


==Operating systems with support for the MS-DOS API== ==Operating systems with native support==
* ] - Most widespread incarnation * ] – most widespread implementation
* ] - IBM version * ] – IBM OEM version of MS-DOS
* ] 1.x – Microsoft/IBM successor to MS-DOS and PC&nbsp;DOS
* ] - Digital Research clone
* ] – ] created by ] and ] in ]
⚫ * ] - Read only memory version
* ] – Digital Research DOS family, including ], ], ], etc.
⚫ * ] - Free, open source
* ] – PhysTechSoft & Paragon DOS clone, including ]
* ] - 1.x, 2.x, 3.x, and 9x were based on DOS
⚫ * ] – Datalight ROM DOS version
* ] – ] version
⚫ * ] – Free, open source DOS clone
* ] (] and ] versions)
* ] – contains MS-DOS 7.0
* ] – contains MS-DOS 7.1
* ] – contains MS-DOS 7.1
* ] – contains MS-DOS 8.0


==Programs with support for the MS-DOS API== ==Operating systems with DOS emulation layer==
* ] (3.1 only) with ] – Digital Research CP/M-86-based OS with optional PC&nbsp;DOS emulator
⚫ * ] for ]
* ] – Digital Research CDOS family with built-in PC&nbsp;DOS emulator
* ] – a stripped-down single-user variant of Concurrent PC&nbsp;DOS 4.1–5.0
* ] – Digital Research/Novell MDOS family including ], ], etc.
* ] (2.x and later) – IBM operating system using a fully-licensed MS-DOS 5.0 in a ]
* ] (all versions except 64-bit editions and 32-bit ARM editions)

==Other emulators==
⚫ * ] for ]
* ] for ] * ] for ]
* ] * ]
* ]


==See also== ==See also==
* ] * ]
* ] * ] (RBIL)
* ] * ]
* ] * ] (DPMI)
* ]
* ] * ]
* ]


==References== ==References==
⚫ * ''Microsoft MS-DOS Programmer's Reference - The Official Technical Reference to MS-DOS'', Microsoft Press, 1993 ISBN 1556155468
* ''The MS-DOS Encyclopedia'', Microsoft Press, 1988, ISBN 1556151748
⚫ * ''The Programmer's PC Sourcebook'' by Thom Hogan, Microsoft Press, 1991 ISBN 155615321X
⚫ * (a.k.a. RBIL, Ralf Brown's Interrupt List)
⚫ *
{{Reflist}} {{Reflist}}

==Further reading==
* {{Cite book |editor-first1=Jim |editor-last1=Beley |editor-first2=Barry |editor-last2=Preppernau |editor-first3=Pam |editor-last3=Beason |editor-first4=Andrea |editor-last4=Lewis |editor-first5=David |editor-last5=Rygmyr |author-first1=Howard |author-last1=Bornstein |author-first2=Lawrence |author-last2=Bredehoeft |author-first3=Ray |author-last3=Duncan |author-first4=Carol |author-last4=Morris |author-first5=David |author-last5=Rose <!-- |author-link5=David Rose --> |author-first6=John |author-last6=Socha |author-link6=John Socha |author-first7=Jim |author-last7=Tomlin |author-first8=Kathleen |author-last8=Vian |author-first9=Van |author-last9=Wolverton |title=MS-DOS (Versions 1.0-3.2) Technical Reference Encyclopedia |contribution=Technical advisors |contributor-first1=Paul |contributor-last1=Allen |contributor-link1=Paul Allen |contributor-first2=Bill |contributor-last2=Gates |contributor-link2=Bill Gates |contributor-first3=Adrian |contributor-last3=King |contributor-first4=Chris |contributor-last4=Larson |contributor-first5=Gordon |contributor-last5=Letwin |contributor-link5=Gordon Letwin |contributor-first6=Bob |contributor-last6=O'Rear |contributor-link6=Bob O'Rear |contributor-first7=Tim |contributor-last7=Paterson |contributor-link7=Tim Paterson |contributor-first8=Chris |contributor-last8=Peters |contributor-first9=Bruce |contributor-last9=Phillips |contributor-first10=Aaron |contributor-last10=Reynolds |contributor-link10=Aaron R. Reynolds |contributor-first11=Betty |contributor-last11=Stillmaker |contributor-first12=Mark |contributor-last12=Zbikowski |contributor-link12=Mark Zbikowski |date=1986 |edition=Original withdrawn |publisher=] |series=Microsoft Reference Library |volume=1 |location=Redmond, Washington, USA |isbn=0-914845-69-1 |lccn=86-8640 |oclc=635600205}} (xvii+1053 pages; 29&nbsp;cm) (NB. This original edition contains flowcharts of the internal workings of the system. It was withdrawn by Microsoft before mass-distribution in 1986 because it contained many factual errors as well as some classified information which should not have been published. Few printed copies survived. It was replaced by a completely reworked edition in 1988. )
* {{Cite book |title=The MS-DOS Encyclopedia: versions 1.0 through 3.2 |author-first1=Ray |author-last1=Duncan |author-first2=Steve |author-last2=Bostwick |author-first3=Keith |author-last3=Burgoyne |author-first4=Robert A. |author-last4=Byers |author-first5=Thom |author-last5=Hogan |author-first6=Jim |author-last6=Kyle |author-first7=Gordon |author-last7=Letwin |author-link7=Gordon Letwin |author-first8=Charles |author-last8=Petzold |author-link8=Charles Petzold |author-first9=Chip |author-last9=Rabinowitz |author-first10=Jim |author-last10=Tomlin |author-first11=Richard |author-last11=Wilton |author-first12=Van |author-last12=Wolverton |author-first13=William |author-last13=Wong |author-first14=JoAnne |author-last14=Woodcock |contribution=Technical advisors |contributor-first1=Mark |contributor-last1=Zbikowski |contributor-link1=Mark Zbikowski |contributor-first2=Paul |contributor-last2=Allen |contributor-link2=Paul Allen |contributor-first3=Steve |contributor-last3=Ballmer |contributor-link3=Steve Ballmer |contributor-first4=Reuben |contributor-last4=Borman |contributor-first5=Rob |contributor-last5=Borman |contributor-first6=John |contributor-last6=Butler |contributor-first7=Chuck |contributor-last7=Carroll |contributor-first8=Mark |contributor-last8=Chamberlain |contributor-first9=David |contributor-last9=Chell |contributor-first10=Mike |contributor-last10=Colee |contributor-first11=Mike |contributor-last11=Courtney |contributor-first12=Mike |contributor-last12=Dryfoos |contributor-first13=Rachel |contributor-last13=Duncan |contributor-first14=Kurt |contributor-last14=Eckhardt |contributor-first15=Eric |contributor-last15=Evans |contributor-first16=Rick |contributor-last16=Farmer |contributor-first17=Bill |contributor-last17=Gates |contributor-link17=Bill Gates |contributor-first18=Michael |contributor-last18=Geary |contributor-first19=Bob |contributor-last19=Griffin |contributor-first20=Doug |contributor-last20=Hogarth |contributor-first21=James W. |contributor-last21=Johnson |contributor-first22=Kaamel |contributor-last22=Kermaani |contributor-first23=Adrian |contributor-last23=King |contributor-first24=Reed |contributor-last24=Koch |contributor-first25=James |contributor-last25=Landowski |contributor-first26=Chris |contributor-last26=Larson |contributor-first27=Thomas |contributor-last27=Lennon |contributor-first28=Dan |contributor-last28=Lipkie |contributor-first29=Marc |contributor-last29=McDonald |contributor-link29=Marc McDonald |contributor-first30=Bruce |contributor-last30=McKinney |contributor-first31=Pascal |contributor-last31=Martin |contributor-first32=Estelle |contributor-last32=Mathers |contributor-first33=Bob |contributor-last33=Matthews <!-- |contributor-link33=Robert Matthews (scientist)??? --> |contributor-first34=David |contributor-last34=Melin |contributor-first35=Charles |contributor-last35=Mergentime |contributor-first36=Randy |contributor-last36=Nevin |contributor-first37=Dan |contributor-last37=Newell |contributor-first38=Tani |contributor-last38=Newell |contributor-first39=David |contributor-last39=Norris |contributor-first40=Mike |contributor-last40=O'Leary |contributor-first41=Bob |contributor-last41=O'Rear |contributor-link41=Bob O'Rear |contributor-first42=Mike |contributor-last42=Olsson |contributor-first43=Larry |contributor-last43=Osterman |contributor-first44=Ridge |contributor-last44=Ostling |contributor-first45=Sunil |contributor-last45=Pai |contributor-first46=Tim |contributor-last46=Paterson |contributor-link46=Tim Paterson |contributor-first47=Gary |contributor-last47=Perez |contributor-first48=Chris |contributor-last48=Peters |contributor-first49=Charles |contributor-last49=Petzold |contributor-link49=Charles Petzold |contributor-first50=John |contributor-last50=Pollock |contributor-first51=Aaron |contributor-last51=Reynolds |contributor-link51=Aaron R. Reynolds |contributor-first52=Darryl |contributor-last52=Rubin |contributor-first53=Ralph |contributor-last53=Ryan |contributor-first54=Karl |contributor-last54=Schulmeisters |contributor-first55=Rajen |contributor-last55=Shah |contributor-first56=Barry |contributor-last56=Shaw |contributor-first57=Anthony |contributor-last57=Short |contributor-first58=Ben |contributor-last58=Slivka |contributor-first59=Jon |contributor-last59=Smirl |contributor-first60=Betty |contributor-last60=Stillmaker |contributor-first61=John |contributor-last61=Stoddard |contributor-first62=Dennis |contributor-last62=Tillman |contributor-first63=Greg |contributor-last63=Whitten |contributor-first64=Natalie |contributor-last64=Yount |contributor-first65=Steve |contributor-last65=Zeck |date=1988 |edition=Completely reworked |publisher=] |location=Redmond, Washington, USA |isbn=1-55615-049-0 |lccn=87-21452 |oclc=16581341}} (xix+1570 pages; 26&nbsp;cm) (NB. This edition was published in 1988 after extensive rework of the withdrawn 1986 first edition by a different team of authors. )
* {{Cite book |title=The New Peter Norton Programmer's Guide to the IBM PC & PS/2 |first1=Peter |last1=Norton |authorlink1=Peter Norton|first2=Richard |last2=Wilton |publisher=Microsoft Press |year=1987 |ISBN=1-55615-131-4}}
* {{cite book |title=Advanced MS-DOS Programming: The Microsoft Guide for Assembly Language and C Programmers |author=Ray Duncan |publisher=Microsoft Press |year=1988 |isbn=0914845772 |url-access=registration |url=https://archive.org/details/advancedmsdosmic00dunc }}
⚫ * {{Cite book |title=The Programmer's PC Sourcebook |first=Thom |last=Hogan |publisher=Microsoft Press |year=1991 |ISBN=155615321X}}
⚫ * {{Cite book |title=MS-DOS Programmer's Reference - The Official Technical Reference to MS-DOS |publisher=Microsoft Press |year=1993 |ISBN=1556155468}}
*
* {{cite book |publisher=] |date=August 1997 |title=OpenDOS Developer's Reference Series &mdash; OpenDOS Programmer's Guide &mdash; System and Programmer's Guide |id=Caldera Part No. 200-DOPG-003 |url=http://www.drdos.net/documentation/sysprog/httoc.htm |url-status=dead |archive-url=https://web.archive.org/web/20171007025631/http://www.drdos.net/documentation/sysprog/httoc.htm |archive-date=2017-10-07 |access-date=2012-06-28 }} (Printed in the UK.)

==External links==
⚫ * (a.k.a. RBIL, ])
⚫ * <!-- http://www.delorie.com/djgpp/doc/rbinter/ -->
*
* {{Webarchive|url=https://web.archive.org/web/20111013235614/http://spike.scu.edu.au/~barry/interrupts.html |date=2011-10-13 }}
{{Disk operating systems}}


] ]
Line 559: Line 612:
] ]
] ]

]
]

Latest revision as of 19:18, 19 November 2024

API of the MS-DOS operating system
This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (May 2015) (Learn how and when to remove this message)

The DOS API is an API which originated with 86-DOS and is used in MS-DOS/PC DOS and other DOS-compatible operating systems. Most calls to the DOS API are invoked using software interrupt 21h (INT 21h). By calling INT 21h with a subfunction number in the AH processor register and other parameters in other registers, various DOS services can be invoked. These include handling keyboard input, video output, disk file access, program execution, memory allocation, and various other activities. In the late 1980s, DOS extenders along with the DOS Protected Mode Interface (DPMI) allow the programs to run in either 16-bit or 32-bit protected mode and still have access to the DOS API.

History of the DOS API

The original DOS API in 86-DOS and MS-DOS 1.0 was designed to be functionally compatible with CP/M. Files were accessed using file control blocks (FCBs). The DOS API was greatly extended in MS-DOS 2.0 with several Unix concepts, including file access using file handles, hierarchical directories and device I/O control. In DOS 3.1, network redirector support was added. In MS-DOS 3.31, the INT 25h/26h functions were enhanced to support hard disks greater than 32 MB. MS-DOS 5 added support for using upper memory blocks (UMBs). After MS-DOS 5, the DOS API was unchanged for the successive standalone releases of DOS.

The DOS API and Windows

In Windows 9x, DOS loaded the protected-mode system and graphical shell. DOS was usually accessed from a virtual DOS machine (VDM) but it was also possible to boot directly to real mode MS-DOS 7.0 without loading Windows. The DOS API was extended with enhanced internationalization support and long filename support, though the long filename support was only available in a VDM. With Windows 95 OSR2, DOS was updated to 7.1, which added FAT32 support, and functions were added to the DOS API to support this. Windows 98 and Windows ME also implement the MS-DOS 7.1 API, though Windows ME reports itself as MS-DOS 8.0.

Windows NT and the systems based on it (e.g. Windows XP and Windows Vista) are not based on MS-DOS, but use a virtual machine, NTVDM, to handle the DOS API. NTVDM works by running a DOS program in virtual 8086 mode (an emulation of real mode within protected mode available on 80386 and higher processors). NTVDM supports the DOS 5.0 API. DOSEMU for Linux uses a similar approach.

Interrupt vectors used by DOS

The following is the list of interrupt vectors used by programs to invoke the DOS API functions.

Interrupt vector Description Version Notes
20h Terminate program 1.0+ Implemented in DOS kernel
21h Main DOS API 1.0+ Implemented in DOS kernel
22h Program terminate address 1.0+ Return address in calling program
23h Control-C handler address 1.0+ Default handler is in the command shell (usually COMMAND.COM)
24h Critical error handler address 1.0+ Default handler is in the command shell (usually COMMAND.COM)
25h Absolute disk read 1.0+ Implemented in DOS kernel, enhanced in DOS 3.31 to support up to 2 GB partitions
26h Absolute disk write 1.0+ Implemented in DOS kernel, enhanced in DOS 3.31 to support up to 2 GB partitions
27h Terminate and stay resident 1.0+ Implemented in COMMAND.COM in DOS 1.0, DOS kernel in DOS 2.0+
28h Idle callout 2.0+ Called by DOS kernel when waiting for input
29h Fast console output 2.0+ Implemented by the built-in console device driver or a replacement driver like ANSI.SYS
2Ah Networking and critical section 3.0+ Called by DOS kernel to interface with networking software
2Bh Unused
2Ch Unused
2Dh Unused
2Eh Reload transient 2.0+ Implemented in COMMAND.COM
2Fh Multiplex 3.0+ Implemented in DOS kernel and various programs (PRINT, MSCDEX, DOSKEY, APPEND, etc.) depending on subfunction number

DOS INT 21h services

The following is the list of functions provided via the DOS API primary software interrupt vector.

AH Description Version
00h Program terminate 1.0+
01h Character input 1.0+
02h Character output 1.0+
03h Auxiliary input 1.0+
04h Auxiliary output 1.0+
05h Printer output 1.0+
06h Direct console I/O 1.0+
07h Direct console input without echo 1.0+
08h Console input without echo 1.0+
09h Display string 1.0+
0Ah Buffered keyboard input 1.0+
0Bh Get input status 1.0+
0Ch Flush input buffer and input 1.0+
0Dh Disk reset 1.0+
0Eh Set default drive 1.0+
0Fh Open file 1.0+
10h Close file 1.0+
11h Find first file 1.0+
12h Find next file 1.0+
13h Delete file 1.0+
14h Sequential read 1.0+
15h Sequential write 1.0+
16h Create or truncate file 1.0+
17h Rename file 1.0+
18h Reserved 1.0+
19h Get default drive 1.0+
1Ah Set disk transfer address 1.0+
1Bh Get allocation info for default drive 1.0+
1Ch Get allocation info for specified drive 1.0+
1Dh Reserved 1.0+
1Eh Reserved 1.0+
1Fh Get disk parameter block for default drive 1.0+
20h Reserved 1.0+
21h Random read 1.0+
22h Random write 1.0+
23h Get file size in records 1.0+
24h Set random record number 1.0+
25h Set interrupt vector 1.0+
26h Create PSP 1.0+
27h Random block read 1.0+
28h Random block write 1.0+
29h Parse filename 1.0+
2Ah Get date 1.0+
2Bh Set date 1.0+
2Ch Get time 1.0+
2Dh Set time 1.0+
2Eh Set verify flag 1.0+
2Fh Get disk transfer address 2.0+
30h Get DOS version 2.0+
31h Terminate and stay resident 2.0+
32h Get disk parameter block for specified drive 2.0+
33h Get or set Ctrl-Break 2.0+
34h Get InDOS flag pointer 2.0+
35h Get interrupt vector 2.0+
36h Get free disk space 2.0+
37h Get or set switch character 2.0+
38h Get or set country info 2.0+
39h Create subdirectory 2.0+
3Ah Remove subdirectory 2.0+
3Bh Change current directory 2.0+
3Ch Create or truncate file 2.0+
3Dh Open file 2.0+
3Eh Close file 2.0+
3Fh Read file or device 2.0+
40h Write file or device 2.0+
41h Delete file 2.0+
42h Move file pointer 2.0+
43h Get or set file attributes 2.0+
44h I/O control for devices 2.0+
45h Duplicate handle 2.0+
46h Redirect handle 2.0+
47h Get current directory 2.0+
48h Allocate memory 2.0+
49h Release memory 2.0+
4Ah Reallocate memory 2.0+
4Bh Execute program 2.0+
4Ch Terminate with return code 2.0+
4Dh Get program return code 2.0+
4Eh Find first file 2.0+
4Fh Find next file 2.0+
50h Set current PSP 2.0+
51h Get current PSP 2.0+
52h Get DOS internal pointers (SYSVARS) 2.0+
53h Create disk parameter block 2.0+
54h Get verify flag 2.0+
55h Create program PSP 2.0+
56h Rename file 2.0+
57h Get or set file date and time 2.0+
58h Get or set allocation strategy 2.11+
59h Get extended error info 3.0+
5Ah Create unique file 3.0+
5Bh Create new file 3.0+
5Ch Lock or unlock file 3.0+
5Dh File sharing functions 3.0+
5Eh Network functions 3.0+
5Fh Network redirection functions 3.0+
60h Qualify filename 3.0+
61h Reserved 3.0+
62h Get current PSP 3.0+
63h Get DBCS lead byte table pointer 3.0+
64h Set wait for external event flag 3.2+
65h Get extended country info 3.3+
66h Get or set code page 3.3+
67h Set handle count 3.3+
68h Commit file 3.3+
69h Get or set media id 4.0+
6Ah Commit file 4.0+
6Bh Reserved 4.0+
6Ch Extended open/create file 4.0+

Operating systems with native support

Operating systems with DOS emulation layer

Other emulators

See also

References

  1. Ray Duncan (1988). Advanced MS-DOS Programming: The Microsoft Guide for Assembly Language and C Programmers. Microsoft Press. ISBN 0914845772.

Further reading

External links

Disk operating systems (DOS)
MS-DOS, IBM PC DOS,
compatible systems
Other x86
  • 4680 OS
  • 4690 OS
  • 86-DOS
  • ADOS
  • Concurrent CP/M-86
  • Concurrent DOS
  • CP/M-86
  • CP/K
  • Datapac System Manager
  • DOS Plus
  • K8918-OS
  • FlexOS
  • MP/M-86
  • Multiuser DOS
  • NetWare PalmDOS
  • Novell DOS
  • OpenDOS
  • PC-MOS/386
  • REAL/32
  • SB-86
  • SCP1700
  • Towns OS
  • TurboDOS
    • Other platforms
    Categories: