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The original Apple OS documents (pictures)

Work orders between a developer and Steve Jobs show how the Apple II OS was built, along with schematics from Steve Wozniak and the the final operating system code.

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James Martin
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1 of 22 James Martin/CNET

Origins of Apple's DOS code

SANTA CRUZ MOUNTAINS, Calif. -- Without a disk drive, the Apple II might never have become one of the most iconic computers in history. But Apple desperately needed a disk operating system to run its hard drives. Newly surfaced documents illustrate the process that led to the creation of that DOS.
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2 of 22 James Martin/CNET

The original Apple DOS documents, April 10, 1978

Communications between Apple's Steve Jobs and developer Robert Shepardson discuss the components of the Apple II disk operating system, including a file manager, a BASIC and Applesoft BASIC interface, and disk copying, recovery, and backup utilities.
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3 of 22 James Martin/CNET

Modifications

This letter from Shepardson to Jobs on June 26, 1978, states the changes on the development work which will be delivered in just one day, for a cost of $500.
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4 of 22 James Martin/CNET

Damer at the DigiBarn

Bruce Damer, founder of the DigiBarn computer museum in the Santa Cruz Mountains of California, talks about the documents, and about the history of the Apple II computer.
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5 of 22 James Martin/CNET

A disk operating system for $13,000

The price paid to the developer for building the first Apple OS? $13,000. With no additional royalties.
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6 of 22 James Martin/CNET

A list of modifications

Hand-written documents list modifications Apple needed to the DOS in June 1978. The new operating system was to be rolled out that October.
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7 of 22 James Martin/CNET

Just eight chips

Over Christmas of 1977 Woz designed this single board interface to run two floppy drives. He did it with just eight chips, while other disk controllers usually needed dozens.
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8 of 22 James Martin/CNET

More modifications

Another document showing modifications to the DOS required by Apple.
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9 of 22 James Martin/CNET

Breakout on cassette

For the first year of the Apple II, users had only a cassette drive to load or save with.
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10 of 22 James Martin/CNET

Bugs memo

This memo detailed some of the debugging work that would be done on the new Apple disk operating system.
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11 of 22 James Martin/CNET

Price list

An official price list for the Apple II.
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DigiBarn's Damer is frequently sent unsolicited pieces of computer history. He had no idea what the Apple DOS documents, sent to him by developer Paul Laughton, contained when he received them.
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13 of 22 James Martin/CNET

Instructions

Hand-written instructions for the Apple DOS.
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14 of 22 James Martin/CNET

Apple II disk

A 5.25-inch floppy disk for the Apple II. Without the Apple DOS, which the company commissioned from Shepardson Microsystems, Apple might never have become the computer giant we know today.
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15 of 22 James Martin/CNET

The controller

The disk controller Wozniak designed held up against a schematic for its design.
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16 of 22 James Martin/CNET

Woz's innovative disk controller

Steve Wozniak's circuit diagrams for his floppy disk controller -- which are considered groundbreaking among computer history experts -- alongside one of the actual boards.
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17 of 22 James Martin/CNET

Woz specs

In the upper right corner of the sheet in front, you can see that this was a diagram by Steve Wozniak. It is the design spec for his groundbreaking disk drive controller.
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18 of 22 James Martin/CNET

Head step timing

A document spells out the head step timing for the Apple disk operating system.
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19 of 22 James Martin/CNET

Pin assignments

Apple disk controller pin assignments from the original disk operating system code.
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20 of 22 James Martin/CNET

Original code

Damer and the DigiBarn are hoping to find volunteers willing to hand-code the original DOS program.
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21 of 22 James Martin/CNET

Human translation

Apple DOS code printed out. The right column shows the human translation of what the command does.
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22 of 22 James Martin/CNET

To be read by actual people

More of the Apple DOS code printed out.

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