View source for DOS Wedge

{{Short description|Software}}
{{Infobox software 
| name                   = DOS Wedge
| logo                   = 
| screenshot             = 
| screenshot_size        = 
| caption                = 
| other_names            = DOS Support,<br />DOS MANAGER
| author                 = Bob Fairbairn, Bill Seiler
| developer              = [[Commodore International]]
| released               = {{Start date and age|1982}}
| discontinued           = yes
| latest release version = 
| latest release date    = 
| programming language   = [[MOS Technology 6502|MOS 6502]] [[assembly language]]
| operating system       = [[Commodore 64]], [[VIC-20]]
| included with          = [[Commodore 1541]],<br />C64 Macro Assembler
| replaced_by            = 
| language               = English
| genre                  = [[System software]]
| license                = 
| website                = 
}}

The '''DOS Wedge''' is a piece of [[Commodore 64]] [[system software]] that was popular in its time. It was written by Bob Fairbairn, and was included by [[Commodore International|Commodore]] (CBM) on the [[Commodore 1541|1541 disk drive]] Test/Demo Disk (filename: "'''DOS 5.1'''") and also packaged with the [[Commodore 64 Macro Assembler Development System|C64 Macro Assembler]] (filename: "'''DOS WEDGE64'''"). The DOS Wedge was referred to in the 1541 drive manual as '''DOS Support''' and on the software startup screen as '''DOS MANAGER'''. The original design was developed by Bill Seiler.

The Wedge made [[Commodore DOS|disk operations]] in [[Commodore BASIC|BASIC 2.0]] significantly easier by introducing several [[reserved word|keyword]] shortcuts. The DOS Wedge became somewhat of a [[de facto]] standard, with third-party vendors such as [[Epyx]] often incorporating identical commands into fastloader cartridges and other Commodore 64 expansion devices. ''[[COMPUTE!'s Gazette]]'' published several [[type-in program|type-in]] variations on the DOS Wedge, including a [[Commodore 128|C128]] version in its February 1987 issue (see External links, below).

The original Commodore DOS Wedge was a 1-[[kilobyte|KB]] program written in [[MOS Technology 6502|MOS 6502]] [[assembly language]]. It resided in the otherwise unused memory block [[hexadecimal|$]]CC00&ndash;$CFFF (52224&ndash;53247) and worked by altering BASIC's "CHRGET" [[subroutine]] at $0073 (115) so that each character passing by the BASIC interpreter would be checked for wedge commands, and the associated "wedged-in" routines run if needed.

==DOS Wedge functions==
Any command that contains an {{code|@}} symbol may substitute {{code|>}} instead, if desired.
{{aligned table|cols=2|col1header=on|col1class=monospaced|col1align=left|class=wikitable
|/''filename''   | Load a BASIC program into RAM
|%''filename''   | Load a machine language program into RAM
|↑''filename''   | Load a BASIC program into RAM and then automatically run it
|←''filename''  | Save a BASIC program to disk
|@  | Display (and clear) the disk drive status
|@$ | Display the disk directory without overwriting the BASIC program in memory
|@''command''    | Execute a disk drive command (e.g. {{mono|S0:''filename'', V0:, I0:}})
|@Q | Deactivate the DOS Wedge
}}

==See also==
*[[Comparison of command shells]]

==References==
*CBM Professional Computer Division (1982). ''Commodore 64 Macro Assembler Development System Manual''. West Chester, PA: Commodore Business Machines. Chapter 5.0. Additional BASIC Disk Commands.

==External links==
*[http://www.atarimagazines.com/compute/issue41/Commodore_DOS_Wedges_An_Overview.php Commodore DOS Wedges: An Overview] - [[Jim Butterfield]], ''[[COMPUTE!]]'', October 1983.
*[http://artofhacking.com/IET/C-64/DOSWEDGE.DOC DOS Wedge documentation (MS Word format)] {{Webarchive|url=https://web.archive.org/web/20060505164031/http://artofhacking.com/IET/C-64/DOSWEDGE.DOC |date=2006-05-05 }}
*[http://project64.c64.org/misc/assembler.txt Commodore 64 Macro Assembler Development System Manual]
*[http://www.devili.iki.fi/pub/Commodore/docs/magazines/gazette/1987/02feb/feb87-128DOSWedgeA.jpg ''COMPUTE!'s Gazette'' February 1987 issue: "DOS Wedge 128" (Part A)], [http://www.devili.iki.fi/pub/Commodore/docs/magazines/gazette/1987/02feb/feb87-128DOSWedgeB.jpg (Part B)]
*[https://web.archive.org/web/20060318153059/http://www.portcommodore.com/cbmloading.php?path=main-cbmidx-cbminfo Commodore Disk Loading Basics]
*[http://project64.c64.org/hw/1541d10a.zip Commodore 1541 Drive Manual (ZIPped text file)]

[[Category:Commodore 64 software]]
[[Category:Command shells]]
[[Category:Assembly language software]]