1sc

.1scSuperCalc 1.0 Spreadsheet

Lotus Development Corporation · 1983

Developer
Lotus Development Corporation
Category
Spreadsheets
MIME Type
application/vnd.lotus-1-2-3
First Released
1983
Open Format
No
File Signature
Not readily available or consistently defined for this legacy format.
At a Glance
.1sc
SuperCalc 1.0 Spreadsheet

A file format for spreadsheets created by early versions of Lotus 1-2-3.

Reviewed on May 4, 2026
Compression
Compressed
Transparency
No
Editability
Low
Best for
Legacy data storage

Key Features

  • Stores tabular data and associated formulas.
  • Supports basic charting and graphing capabilities.
  • Includes formatting options for text and cells.
  • Proprietary binary format specific to Lotus 1-2-3.

Best For

  • Maintaining compatibility with very old Lotus 1-2-3 data.
  • Serving as a historical data archive.
  • Situations where only legacy software is available.

Less Ideal For

  • Modern collaboration and cloud-based workflows.
  • Sharing data with users of contemporary spreadsheet software.
  • Creating complex, interactive, or large-scale datasets.
  • Storing data that requires advanced features like macros or pivot tables.

Common Use Cases

  • Archiving historical financial data.
  • Accessing legacy business records created in Lotus 1-2-3.
  • Data recovery for old Lotus 1-2-3 installations.
  • Educational purposes to study early spreadsheet software.

How to Open It

  1. Attempt to open with modern spreadsheet software like Microsoft Excel or LibreOffice Calc; they may offer import functionality for older formats.
  2. Seek out specialized legacy software emulators or conversion tools designed for Lotus 1-2-3 files.
  3. If you have an old computer with Lotus 1-2-3 installed, you can open the file directly within that environment.

What is a .1sc file?

The .1sc file extension is primarily associated with early versions of the Lotus 1-2-3 spreadsheet software. This format was once a dominant force in the business world, enabling users to create and manage complex financial data, charts, and tables. While largely superseded by modern spreadsheet applications, .1sc files represent a significant piece of computing history. They contain the raw data and formatting information essential for recalculating budgets, forecasts, and other critical business insights from that era.

Programs That Open .1sc Files

PlatformProgram
WindowsLibreOffice CalcFree
Microsoft ExcelPaidOfficial
macOSLibreOffice CalcFree
Microsoft ExcelPaidOfficial
LinuxLibreOffice CalcFree
Web BrowserGoogle Sheets (via import)Free

How to Convert .1sc Files

FormatMethod
.CSVLibreOffice Calc, Microsoft Excel
.XLSXLibreOffice Calc, Microsoft Excel

Common Problems with .1sc Files

⚠️ File is unreadable by modern software.
Use conversion tools or software with import capabilities like LibreOffice Calc or Microsoft Excel, which may attempt to parse legacy formats.
⚠️ Formulas or formatting are lost during conversion.
Manual re-entry or careful checking after conversion is often necessary, as not all features translate perfectly between old and new spreadsheet formats.

Frequently Asked Questions

Can I open a .1sc file on a Mac?

Yes, you can open .1sc files on a Mac using compatible spreadsheet software like LibreOffice Calc or Microsoft Excel, which often have import features for older file types.

Is .1sc a text file?

No, .1sc files are binary files, not plain text files. This means their content is not directly human-readable without specialized software.

What is the successor to Lotus 1-2-3 files?

While Lotus 1-2-3 itself was eventually discontinued, its data can often be imported into modern spreadsheet applications like Microsoft Excel or LibreOffice Calc, which use formats like .xlsx or .ods.

Technical Details

.1sc files are binary files that store spreadsheet data, formulas, and formatting. They were part of the Lotus 1-2-3 suite, which was a trailblazer in the spreadsheet software market. The structure is proprietary and not easily human-readable, relying on specific parsers within Lotus 1-2-3 or compatible software to interpret and display the content.

Did You Know?

Lotus 1-2-3 was one of the first 'killer applications' for IBM PCs, driving their adoption in business.
The name '1-2-3' was chosen because it combined three key features: spreadsheet, graphing, and database management.

Security Information

Like any file, .1sc files can potentially contain malicious code if they originate from an untrusted source or have been tampered with. Always scan files from unknown sources with antivirus software before opening, especially when using older or less common software.

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