David Bradley (engineer)
Encyclopedia
David Bradley was one of the twelve engineers who worked on the original IBM PC
, developing the computer ROM BIOScode. He is credited by some for inventing the "Control-Alt-Delete
" key combination that was used to reboot
the computer.
to be used by end users — it was meant to be used by people writing programs or documentation, so that they could reboot their computers without powering them down. This was useful since after a computer was powered down, it was necessary to wait a few seconds before powering it up again to avoid potential damage to the power supply
. Since software developers and technical writers would need to restart a computer many times, this key combination was a big time-saver. Bradley chose this key combination because it is practically impossible to accidentally press this combination of keys on a standard keyboard. However, the key combination was revealed to the public when developers found it useful, and at the 20th anniversary of the IBM PC, while on a panel with Bill Gates
, Bradley said "I may have invented it (control-alt-delete), but I think Bill [Gates] made it famous".
According to another account, the man responsible for selecting Control-Alt-Delete was Michael Donald Wise. He selected that combination of keys in 1975 as he built the first true PC, Sphere 1
, which predated the IBM PC by six years.
as Assembleur sur IBM PC (Dunod, ISBN 2-225-80695-0), Russian ("Radio" Publishing House, Moscow), and Bulgarian ("Technica" Publishing house, 1989).
Bradley holds seven U.S. patents.
Bradley has been adjunct professor of electrical and computer engineering at Florida Atlantic and at North Carolina State University
.
Much of Bradley's career has been at IBM. Bradley began at IBM after receiving a PhD from Purdue in 1975. He worked on the Series/1
system. In 1978 he developed the I/O
system for the System/23 Datamaster
.
In 1980 Bradley was one of twelve engineers developing the first IBM Personal Computer. Bradley developed the ROM
BIOS
. That got him promoted to manage the BIOS and diagnostics for the IBM PC XT. In 1983 Bradley formed the Personal Systems Architecture Department. In 1984 he helped manage development of the Personal System 2
Model 30.
In November 1987 Bradley became manager of advanced processor design. His group developed the 486/25 Power Platform and the PS/2 Models 90 and 95. In 1991 he became manager of systems architecture for the Entry Systems Technology group. In 1992 he became the architecture manager for the group that developed a personal computer using the PowerPC
RISC microprocessor
.
In 1993 he returned to be the manager of architecture in the PC group.
On January 30, 2004, Bradley retired from IBM.
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
, developing the computer ROM BIOScode. He is credited by some for inventing the "Control-Alt-Delete
Control-Alt-Delete
Control-Alt-Delete is a computer keyboard command on IBM PC compatible systems that can be used to reboot the computer, and summon the task manager or Windows Security in more recent versions of the Microsoft Windows operating system...
" key combination that was used to reboot
Booting
In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the...
the computer.
Control-Alt-Delete
Bradley did not intend Control-Alt-DeleteControl-Alt-Delete
Control-Alt-Delete is a computer keyboard command on IBM PC compatible systems that can be used to reboot the computer, and summon the task manager or Windows Security in more recent versions of the Microsoft Windows operating system...
to be used by end users — it was meant to be used by people writing programs or documentation, so that they could reboot their computers without powering them down. This was useful since after a computer was powered down, it was necessary to wait a few seconds before powering it up again to avoid potential damage to the power supply
Power supply unit (computer)
A power supply unit converts mains AC to low-voltage regulated DC power for the internal components of the computer. Modern personal computers universally use a switched-mode power supply...
. Since software developers and technical writers would need to restart a computer many times, this key combination was a big time-saver. Bradley chose this key combination because it is practically impossible to accidentally press this combination of keys on a standard keyboard. However, the key combination was revealed to the public when developers found it useful, and at the 20th anniversary of the IBM PC, while on a panel with Bill Gates
Bill Gates
William Henry "Bill" Gates III is an American business magnate, investor, philanthropist, and author. Gates is the former CEO and current chairman of Microsoft, the software company he founded with Paul Allen...
, Bradley said "I may have invented it (control-alt-delete), but I think Bill [Gates] made it famous".
According to another account, the man responsible for selecting Control-Alt-Delete was Michael Donald Wise. He selected that combination of keys in 1975 as he built the first true PC, Sphere 1
Sphere 1
The Sphere I was a personal computer completed in 1975 by Michael Donald Wise of Sphere Corporation, of Bountiful, Utah. The Sphere I featured a Motorola 6800 CPU, onboard ROM, Monitor, 4 KB of RAM, and a keyboard with a numeric keypad. Sphere I. The Sphere I was among the earliest microcomputers...
, which predated the IBM PC by six years.
Other accomplishments
Bradley is the author of Assembly Language Programming for the IBM Personal Computer (Simon & Schuster, ISBN 0-13-049171-3, January 1984), also released in FrenchFrench language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
as Assembleur sur IBM PC (Dunod, ISBN 2-225-80695-0), Russian ("Radio" Publishing House, Moscow), and Bulgarian ("Technica" Publishing house, 1989).
Bradley holds seven U.S. patents.
Bradley has been adjunct professor of electrical and computer engineering at Florida Atlantic and at North Carolina State University
North Carolina State University
North Carolina State University at Raleigh is a public, coeducational, extensive research university located in Raleigh, North Carolina, United States. Commonly known as NC State, the university is part of the University of North Carolina system and is a land, sea, and space grant institution...
.
Much of Bradley's career has been at IBM. Bradley began at IBM after receiving a PhD from Purdue in 1975. He worked on the Series/1
IBM Series/1
The IBM Series/1 computer is a 16-bit minicomputer, introduced in 1976, that in many respects competed with other minicomputers of the time, such as the PDP-11 from Digital Equipment Corporation and similar offerings from Data General and HP...
system. In 1978 he developed the I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
system for the System/23 Datamaster
IBM System/23
The System/23 Datamaster was announced by IBM in July 1981, only one month before the IBM PC. The Datamaster was an all-in-one computer with text-mode CRT display, keyboard, processor, memory, and two 8-inch floppy disk drives all contained in one cabinet. The processor was an 8-bit Intel 8085,...
.
In 1980 Bradley was one of twelve engineers developing the first IBM Personal Computer. Bradley developed the ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
. That got him promoted to manage the BIOS and diagnostics for the IBM PC XT. In 1983 Bradley formed the Personal Systems Architecture Department. In 1984 he helped manage development of the Personal System 2
IBM Personal System/2
The Personal System/2 or PS/2 was IBM's third generation of personal computers. The PS/2 line, released to the public in 1987, was created by IBM in an attempt to recapture control of the PC market by introducing an advanced proprietary architecture...
Model 30.
In November 1987 Bradley became manager of advanced processor design. His group developed the 486/25 Power Platform and the PS/2 Models 90 and 95. In 1991 he became manager of systems architecture for the Entry Systems Technology group. In 1992 he became the architecture manager for the group that developed a personal computer using the PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
RISC microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
.
In 1993 he returned to be the manager of architecture in the PC group.
On January 30, 2004, Bradley retired from IBM.