Merlin is a

MOS Technology 6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small t ...

macro assembler Macro (or MACRO) may refer to: Science and technology * Macroscopic, subjects visible to the eye * Macro photography, a type of close-up photography * Image macro, a picture with text superimposed * Monopole, Astrophysics and Cosmic Ray Observato ...

developed by mathematics professor

Glen Bredon Glen Eugene Bredon (August 24, 1932 in Fresno, California – May 8, 2000, in North Fork, California) was an American mathematician who worked in the area of topology. Education and career Bredon received a bachelor's degree from Stanford Unive ...

for the

Apple II The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-m ...

under DOS 3.3. It was published commercially by Southwestern Data Systems, later known as Roger Wagner Publishing. Merlin continued to be updated as successors to the 6502 became available: first the

65C02 The Western Design Center (WDC) 65C02 microprocessor is an enhanced CMOS version of the popular nMOS-based 8-bit MOS Technology 6502. The 65C02 fixed several problems in the original 6502 and added some new instructions, but its main feature ...

and later the 65816 and 65802. A

ProDOS ProDOS is the name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II series computers, and w ...

version was made available as Merlin Pro (this package also included the DOS 3.3 version). The 8-bit version of Merlin was later renamed Merlin 8, and a 16-bit version, dubbed Merlin 16, was released for the

Apple IIGS The Apple IIGS (styled as II), the fifth and most powerful of the Apple II family, is a 16-bit personal computer produced by Apple Computer. While featuring the Macintosh look and feel, and resolution and color similar to the Amiga and Atari ST ...

. Versions for the

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness ...

and

Commodore 128 The Commodore 128, also known as the C128, C-128, C= 128,The "C=" represents the graphical part of the logo. is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the ...

were released as Merlin 64 and Merlin 128 respectively. Merlin includes an integrated source code editor (initially a

line editor In computing, a line editor is a text editor in which each editing command applies to one or more complete lines of text designated by the user. Line editors predate screen-based text editors and originated in an era when a computer operator typic ...

; later versions include a full-screen editor) and also a

disassembler A disassembler is a computer program that translates machine language into assembly language—the inverse operation to that of an assembler. A disassembler differs from a decompiler, which targets a high-level language rather than an assembly lan ...

, called Sourceror. A related utility, Sourceror.FP, can generate a commented disassembly of the Apple II's

Applesoft BASIC Applesoft BASIC is a dialect of Microsoft BASIC, developed by Marc McDonald and Ric Weiland, supplied with the Apple II series of computers. It supersedes Integer BASIC and is the BASIC in ROM in all Apple II series computers after the original ...

, the source code for which had never been released by

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...

, from the customer's own ROM.

Reception

Ahoy! ''Ahoy!'' was a computer magazine published between January 1984 and January 1989 in the US, focusing on all Commodore color computers, but especially the Commodore 64 and Amiga. History The first issue of ''Ahoy!'' was published in January 198 ...

'' called Merlin 64 "an excellent little assembler with many value added features. For ease of use, I couldn't imagine how it could be better ... an outstanding value".

Legacy

On August 24, 2000, what would have been the author's 68th birthday, his widow released all of his Apple II software and

source code In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the wo ...

(e.g.

DOS.MASTER Glen Eugene Bredon (August 24, 1932 in Fresno, California – May 8, 2000, in North Fork, California) was an American mathematician who worked in the area of topology. Education and career Bredon received a bachelor's degree from Stanford Unive ...

) as

public domain software Public-domain software is software that has been placed in the public domain, in other words, software for which there is absolutely no ownership such as copyright, trademark, or patent. Software in the public domain can be modified, distributed, ...

. In January, 2015 a Windows edition of Merlin titled "Merlin 32" was released by Brutal Deluxe.Brutal Deluxe Software: "Merlin 32"
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References

{{reflist Apple II software Assemblers Commodore 64 software Commodore 128 software Public-domain software with source code