# magnetic storage card

> small and thin elongated plastic card with magnetizable layer, used for magnetic data storage in programmable pocket calculators from the 1970s and 1980s

**Wikidata**: [Q123000843](https://www.wikidata.org/wiki/Q123000843)  
**Source**: https://4ort.xyz/entity/magnetic-storage-card

## Summary
A magnetic storage card is a small, thin, elongated plastic card with a magnetizable layer used for storing data in programmable pocket calculators from the 1970s and 1980s. It was primarily used in calculators like the HP-65 and TI-59 to save and load programs and data.

## Key Facts
- First introduced in 1974 with the HP-65, the first programmable scientific handheld calculator with a magnetic card reader
- Used in calculators from Hewlett-Packard (HP-65, HP-67, HP-97, HP-41C) and Texas Instruments (TI-59)
- Dimensions: 71mm × 9.5mm for HP cards
- Storage capacity: 480 bytes for TI-59 cards
- Invented by Hewlett-Packard
- Classified as magnetic memory and a subclass of magnetic storage and magnetic stripe cards

## FAQs
### Q: What was the primary use of magnetic storage cards?
A: Magnetic storage cards were used to store and transfer programs and data between programmable pocket calculators, allowing users to save their work and share programs.

### Q: Which calculators used magnetic storage cards?
A: Major calculators that used magnetic storage cards include the HP-65, HP-67, HP-97, HP-41C from Hewlett-Packard, and the TI-59 from Texas Instruments.

### Q: How much data could a magnetic storage card hold?
A: TI-59 magnetic storage cards could hold 480 bytes of data, while HP cards had similar storage capacities for their time.

## Why It Matters
Magnetic storage cards represented a significant advancement in portable computing during the 1970s and 1980s. Before their introduction, programmable calculators had limited memory and couldn't save programs between sessions. These cards enabled users to store complex calculations, engineering formulas, and custom programs, dramatically expanding the practical utility of handheld calculators. They were particularly valuable for professionals like engineers, scientists, and students who needed to work with sophisticated calculations on the go. The technology also pioneered concepts of portable data storage that would later influence the development of other removable storage media.

## Notable For
- First removable storage medium for handheld programmable calculators
- Enabled program sharing and distribution through pre-programmed cards
- Pioneered portable data storage concepts for mobile computing
- Used in both consumer and professional calculator applications
- Represented a key step in the evolution of personal computing storage

## Body
### Technical Specifications
Magnetic storage cards were typically 71mm long and 9.5mm wide for HP models, with a thin magnetizable layer on one side. The cards were designed to be inserted into a built-in card reader on compatible calculators.

### Historical Development
The technology emerged in 1974 with the HP-65, which was the first programmable scientific handheld calculator to include a magnetic card reader. Texas Instruments followed with the TI-59 in 1977, which also featured magnetic card storage capabilities.

### Manufacturers and Models
Hewlett-Packard produced cards for their HP-65 (1974), HP-67 (1976), HP-97 (1976), and HP-41C (1979) calculators. Texas Instruments manufactured cards for their TI-59 (1977) calculator. Each manufacturer's cards were proprietary to their respective calculator systems.

### Data Storage Method
The magnetizable layer on the card stored binary data as magnetic patterns. When inserted into the calculator's card reader, the device would read or write data by detecting or altering these magnetic patterns.

### Applications
Users could store mathematical programs, engineering calculations, scientific formulas, and other data. Pre-programmed cards were also sold containing specialized software for various professional applications including navigation, aviation calculations, and standard engineering tasks.

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