Dc (computer program)
cross-platform reverse-Polish calculator program
dc (desk calculator) is a cross-platform reverse-Polish calculator which supports arbitrary-precision arithmetic. It was written by Lorinda Cherry and Robert Morris at Bell Labs. dc is one of the oldest Unix utilities, preceding even the development of the C programming language. Like other utilities of that vintage, it has a powerful set of features but terse syntax.
Although the bc calculator program (which uses infix notation) was traditionally implemented on top of dc, the modern GNU implementation of dc bases off of bc.
History
dc is the oldest surviving Unix language program. When Bell Labs, where dc was developed, received a PDP-11, dc—written in B—was the first program to run on the new computer, even before an assembler. Ken Thompson has opined that dc was the very first program written on the machine.
Basic operations
To multiply four and five in dc (note that most of the whitespace is optional):
The results are also available from the commands:
or
This translates into "push four and five onto the stack, then, with the multiplication operator, pop two elements from the stack, multiply them and push the result onto the stack." Then the p command is used to examine (print out to the screen) the top element on the stack. The q command quits the invoked instance of dc.
This brief starts where responsible research should: with the source description of “Dc (computer program)” as cross-platform reverse-Polish calculator program. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as cross-platform reverse-Polish calculator program. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 27, 2026. The linked authority identifier is Q344670. None of the 0 selected statements returned an explicit reference.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Dc (computer program)”, its source revision and the description used here.
- Expand the search: follow Dc (computer program) primary sources, Dc (computer program) archive and computer research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Dc (computer program)”?
- What terminology or title could unlock a more precise catalogue search?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Dc (computer program)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.