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Hard Disk 20: History & Art
The Macintosh Hard Disk 20 is the first hard drive developed by Apple Computer specifically for use with the Macintosh 512K. Introduced on September 17, 1985, it was part of Apple's solution toward completing the Macintosh Office (a suite of integrated business hardware & software) announced in January 1985. It would be over a year more before Apple…
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Hard Disk 20 topic overview
The analysis highlights History and Art as prominent areas in the source structure around Hard Disk 20.
Related topics
24
Source areas
3
Connected nodes
27
Extracted relationships
77
Concept neighborhoods
22
Bridge connections
27
What this topic covers Research coverage
Source areas are shown by the number of related topics found in each part of the analysis. Use smaller areas too: they can reveal specialized angles and content gaps.
Features · 13 topics
Overview · 7 topics
History · 4 topics
Smaller areas are not necessarily less important. They contain fewer connections in this analysis and can be useful for finding specialized angles or coverage gaps.
Key facts & relationships
High-confidence facts extracted from structured source data. Use them as anchors for further research.
Connection
Floppy drive port at 500 kbit/s
Connects to
DB-19 Connector
Cost
US$1,495 (equivalent to $4,475 in 2025)
Design firm
Apple Inc.
Dimensions
3.1 x 9.7 x 10.5 inches (7.9 x 25 x 27 cm)
Discontinued
September 1987 (1987-09)
Explore all related topics Closing gaps
A structured outline of related entities, concepts and subtopics. Open any item to build a new map centered on it.
Browse the complete topic structure, not only the most central items. Less prominent entities and concepts can reveal missing angles, specialized context and useful research gaps. Each item opens a new analysis centered on that subject.
Deeper signals for content research, entity SEO and topical coverage. The plain-language headings explain what each technical view is useful for.
How Hard Disk 20 connects Entity context
Entity context groups extracted connections by relationship type. Counts show recurrence in the analyzed source; the examples are research signals, not claims about importance.
The extracted context around Hard Disk 20 shows recurring relationship patterns in the source. For example, Hard Disk 20 → Apple, Apple's, Apple's HD20, As, At, Finder, Hard Disk, HD20, Hierarchical File System, In, It, Mac, Macintosh, Macintosh File System, Macintosh Plus, MB, RAM, Rodime, ROM, Serial Port Another extracted example is Hard Disk 20 → Apple, Apple-manufactured, April, Hard Disk, HD20, HD20's, However, In, January, Macintosh, Macintosh II, Macintosh Plus, Macintosh XL, Macs, Only Macs, Rodime, ROM, Sales, SCSI, Some. Use these groups to spot repeated connection types before inspecting the individual relationships.
Hard Disk 20
Top relations
related to Features· 28
Hard Disk 20 → Apple, Apple's, Apple's HD20, As, At, Finder, Hard Disk, HD20, Hierarchical File System, In, It, Mac, Macintosh, Macintosh File System, Macintosh Plus, MB, RAM, Rodime, ROM, Serial Port
related to history· 23
Hard Disk 20 → Apple, Apple-manufactured, April, Hard Disk, HD20, HD20's, However, In, January, Macintosh, Macintosh II, Macintosh Plus, Macintosh XL, Macs, Only Macs, Rodime, ROM, Sales, SCSI, Some
related to External links· 13
Hard Disk 20 → Classic Macintosh Preservation, Disk, February, Hard Disk, Info, Mac Systems Compatible, Mac512, May, System, The M0001 Registry Owners, Vintage MacintoshApple Macintosh Before, VintageMacWorld, Wayback Machine
Connection· 1
Hard Disk 20 → Floppy drive port at 500 kbit/s
Connects to· 1
Hard Disk 20 → DB-19 Connector
Cost· 1
Hard Disk 20 → US$1,495 (equivalent to $4,475 in 2025)
Design firm· 1
Hard Disk 20 → Apple Inc.
Dimensions· 1
Hard Disk 20 → 3.1 x 9.7 x 10.5 inches (7.9 x 25 x 27 cm)
Discontinued· 1
Hard Disk 20 → September 1987 (1987-09)
Introduced· 1
Hard Disk 20 → September 17, 1985 (1985-09-17)
Important terminology
Frequent words and multi-word phrases across the lead, headings, infobox and body. Useful for terminology coverage.
Use these terms to understand the vocabulary surrounding the topic, not as a checklist for keyword stuffing.
Hard Disk 20 relationships Subject–Predicate–Object triples
Relationships are represented as Subject → Predicate → Object triples. Confidence describes extraction strength, not the real-world importance of a relationship; lower-confidence rows may be contextual rather than explicit.
TTTA extracted 77 structured relationships around Hard Disk 20. Examples in this analysis include Hard Disk 20 → Connection → Floppy drive port at 500 kbit/s and Hard Disk 20 → Connects to → DB-19 Connector. The table shows each extracted connection, where it came from and its confidence.
Subject
Predicate
Object
Confidence
Src
Hard Disk 20
Connection
Floppy drive port at 500 kbit/s
1.00
infobox
Hard Disk 20
Connects to
DB-19 Connector
1.00
infobox
Hard Disk 20
Cost
US$1,495 (equivalent to $4,475 in 2025)
1.00
infobox
Hard Disk 20
Design firm
Apple Inc.
1.00
infobox
Hard Disk 20
Dimensions
3.1 x 9.7 x 10.5 inches (7.9 x 25 x 27 cm)
1.00
infobox
Hard Disk 20
Discontinued
September 1987 (1987-09)
1.00
infobox
Hard Disk 20
Introduced
September 17, 1985 (1985-09-17)
1.00
infobox
Hard Disk 20
Manufacturer
Apple Inc.
1.00
infobox
Hard Disk 20
Memory
20 MB
1.00
infobox
Hard Disk 20
Power consumption
30 W
1.00
infobox
Hard Disk 20
Type
Hard Disk
1.00
infobox
Hard Disk 20
Weight
7 lbs (3.2 kg)
1.00
infobox
Hard Disk 20
is a
first hard drive developed by Apple Computer specifically for use with the Macintosh 512K
0.90
text
No triples extracted yet.
Related concept clusters Concept neighborhoods
Concept neighborhoods group terms that sit near one another in the extracted graph. They are useful for discovering adjacent language and context, but proximity does not by itself imply a factual relationship.
The concept neighborhoods around Hard Disk 20 bring nearby vocabulary together. In this analysis, examples include Disk, Hard and Drive. Use the clusters to find adjacent concepts and terminology that may deserve separate research.
Hard Disk 20
Disk
Hard
Drive
Macintosh
Drives
Hd20
Also
512k
Code
Port
Use
Floppy
hard disk 20
Disk
Hard
Drive
Macintosh
Floppy
Startup
Drives
Use
Hd20
Also
First
512k
hard drive
Disk
Drive
Hard
Macintosh
First
Drives
Hd20
Also
Floppy
512k
Port
Mb
apple computer
Inc
System
File
Business
Compatible
First
New
Computer
Support
Disk
Hard
512k
macintosh 512k
Hd20
Use
System
512k
Macintosh
Hard
File
512ke
January
Plus
Rom
Drive
macintosh office
Hd20
System
512k
512ke
January
Plus
Rom
Apple's
Code
Scsi
Support
Drives
macintosh plus
Scsi
Hd20
System
512k
Would
512ke
Kb
Rom
Time
Used
January
Plus
hard disk
Disk
Hard
Drive
Macintosh
Floppy
Startup
Drives
Use
Hd20
Also
First
512k
Connections between topic areas Semantic bridges
Semantic bridges connect parts of the graph that would otherwise be more separate. A bridge is a structural signal in this analysis, not a claim that the two topic areas are equivalent.
For Hard Disk 20, one of the stronger structural bridges in this analysis connects Hard Disk 20 with Features. Bridges highlight paths between different parts of the map and can reveal research angles that are easy to miss in a flat list.
Min side: 3
Hard Disk 20 — Features· splits 14 ⟂ 14Hard Disk 20 — Overview· splits 20 ⟂ 8Hard Disk 20 — History· splits 23 ⟂ 5
Map overview Semantic statistics
Number of nodes, edges, triples, density and central hubs. Use it to gauge the size and connectivity of the map.
Hard Disk 20
Nodes28
Edges27
Triples77
Avg. degree1.93
Density0.071429
Components1
Source & methodology
TTTA analyzes the structure around Hard Disk 20 to surface related topics, entities, relationships, concept neighborhoods and bridge connections. Use the map to explore areas such as History & Art, including less central topics that may reveal useful research gaps. Automatically extracted connections are research leads rather than rewritten encyclopedia content.
