Read The 1978 Apple II Source Code
In June 1977 Apple Computer shipped their first
mass-market computer - the Apple II - and Computer History
Museum has posted online the interesting source code of the
device.
The Apple II was fully assembled and ready to
use with any display monitor. The version with 4K of memory
cost $1298. It had color, graphics, sound, expansion slots,
game paddles, and a built-in BASIC programming language.
What it didn't have was a disk drive. Programs and data had to be saved and loaded from cassette tape recorders, which were slow and unreliable. The problem was that disks - even floppy disks - needed both expensive hardware controllers and complex software.
Steve Wozniak solved the first problem. He designed an incredibly clever floppy disk controller using only 8 integrated circuits, by doing in programmed logic what other controllers did with hardware. With some rudimentary software written by Woz and Randy Wigginton, it was demonstrated at the Consumer Electronics Show in January 1978.
But where were they going to get the higher-level software to organize and access programs and data on the disk- Apple only had about 15 employees, and none of them had both the skills and the time to work on it.
The magician who pulled that rabbit out of the hat was Paul Laughton, a contract programmer for Shepardson Microsystems, which was located in the same Cupertino office park as Apple.
On April 10, 1978 Bob Shepardson and Steve Jobs signed a $13,000 one-page contract for a file manager, a BASIC interface, and utilities. It specified that "Delivery will be May 15", which was incredibly aggressive. But, amazingly, "Apple II DOS version 3.1" was released in June 1978.
If you want to take a look to the 1978 source code of Apple II DOS visit the www.computerhistory.org web site. As a note, the material is Copyright 1978 Apple Inc., and may not be reproduced without permission from Apple.
The Apple II was fully assembled and ready to
use with any display monitor. The version with 4K of memory
cost $1298. It had color, graphics, sound, expansion slots,
game paddles, and a built-in BASIC programming language.
What it didn't have was a disk drive. Programs and data had to be saved and loaded from cassette tape recorders, which were slow and unreliable. The problem was that disks - even floppy disks - needed both expensive hardware controllers and complex software.
Steve Wozniak solved the first problem. He designed an incredibly clever floppy disk controller using only 8 integrated circuits, by doing in programmed logic what other controllers did with hardware. With some rudimentary software written by Woz and Randy Wigginton, it was demonstrated at the Consumer Electronics Show in January 1978.
But where were they going to get the higher-level software to organize and access programs and data on the disk- Apple only had about 15 employees, and none of them had both the skills and the time to work on it.
The magician who pulled that rabbit out of the hat was Paul Laughton, a contract programmer for Shepardson Microsystems, which was located in the same Cupertino office park as Apple.
On April 10, 1978 Bob Shepardson and Steve Jobs signed a $13,000 one-page contract for a file manager, a BASIC interface, and utilities. It specified that "Delivery will be May 15", which was incredibly aggressive. But, amazingly, "Apple II DOS version 3.1" was released in June 1978.
If you want to take a look to the 1978 source code of Apple II DOS visit the www.computerhistory.org web site. As a note, the material is Copyright 1978 Apple Inc., and may not be reproduced without permission from Apple.
