IBM Convertible
Encyclopedia
The IBM PC Convertible, released April 3, 1986, was IBM's first laptop
computer and was also the first IBM computer to utilize the 3.5" floppy disk which went on to become the standard. Like modern laptops, it featured power management and the ability to run from batteries. It was the follow-up to the IBM Portable
and was model number 5140. The concept and the design of the body was made by the German industrial designer Richard Sapper
.
It utilized an Intel 80c88 CPU
(a CMOS
version of the Intel 8088
) running at 4.77 MHz, 256 kB of RAM (expandable to 640 kB), dual 720 kB 3.5" floppy drives, and a monochrome CGA
-compatible LCD
screen at a price of $2,000. It weighed 13 pounds (5.8 kg) and featured a built-in carrying handle.
The PC Convertible had expansion capabilities through a proprietary ISA bus
-based port on the rear of the machine. Extension modules, including a small printer and a video output module, could be snapped into place. The machine could also take an internal modem
, but there was no room for an internal hard disk
.
Pressing the power button on the computer did not turn it off, but put the machine into a "suspend" mode. This avoided the long process of booting up. The CMOS 80c88 CPU has a static core
, which means that it can be stopped simply by stopping the system clock oscillator that is driving it, and it will hold its state indefinitely and resume processing at the point it was stopped when the clock signal is restarted, as long as it is kept powered. CMOS circuits use extremely little power when they are not changing state, so an 80c88 that is on but not being clocked uses very little power.
The screen was not very tall, so text characters and graphics were compressed vertically, appearing about half their normal height. The display was capable of resolutions of 80x25 (text), 640x200, and 320x200. Pressing a lever between the two floppy drives just below the display detached the entire screen from the unit. This feature allowed the convenient use of a full-size desktop monitor while at one's desk, an early forerunner of the "docking station" concept.
The machine sold very poorly for a number of reasons. The Convertible was heavy, not much faster than the Portable it replaced (despite the newer CMOS
processor and use of static RAM), didn't come with traditional PC expansion ports (such as serial port
s and a parallel port
) without an add-on, and had a hard-to-read, oddly-shaped LCD
screen (the first screens lacked a backlight
). It also competed against faster portables based on the Intel 80286
that offered optional hard drives, from companies such as Compaq
, and laptops from companies such as Toshiba
and Zenith that were lighter and offered similar specifications, sometimes at half the price. With the screen, the keyboard was also widely criticized.
It was replaced in 1991 by the IBM PS/2 L40 SX, and in Japan by the IBM Personal System/55note, which was the predecessor to the ThinkPad
.
Laptop
A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
computer and was also the first IBM computer to utilize the 3.5" floppy disk which went on to become the standard. Like modern laptops, it featured power management and the ability to run from batteries. It was the follow-up to the IBM Portable
IBM Portable
The IBM Portable Personal Computer 5155 model 68 was an early portable computer developed by IBM after the success of Compaq's suitcase-size portable machine . It was released in February, 1984, and was eventually replaced by the IBM Convertible.The Portable was basically a PC/XT motherboard,...
and was model number 5140. The concept and the design of the body was made by the German industrial designer Richard Sapper
Richard Sapper
Richard Sapper, born 1932 in Munich, is a German industrial designer based in Milan, Italy. He is considered one of the most iconic designers of his generation, his products typically featuring a combination of technical innovation, simplicity of form and an element of wit and surprise...
.
It utilized an Intel 80c88 CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
(a CMOS
CMOS
Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...
version of the Intel 8088
Intel 8088
The Intel 8088 microprocessor was a variant of the Intel 8086 and was introduced on July 1, 1979. It had an 8-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers and the one megabyte address range were unchanged, however...
) running at 4.77 MHz, 256 kB of RAM (expandable to 640 kB), dual 720 kB 3.5" floppy drives, and a monochrome CGA
Color Graphics Adapter
The Color Graphics Adapter , originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card, and the first color computer display standard for the IBM PC....
-compatible LCD
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
screen at a price of $2,000. It weighed 13 pounds (5.8 kg) and featured a built-in carrying handle.
The PC Convertible had expansion capabilities through a proprietary ISA bus
Industry Standard Architecture
Industry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
-based port on the rear of the machine. Extension modules, including a small printer and a video output module, could be snapped into place. The machine could also take an internal modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
, but there was no room for an internal hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
.
Pressing the power button on the computer did not turn it off, but put the machine into a "suspend" mode. This avoided the long process of booting up. The CMOS 80c88 CPU has a static core
Static core
Static core is a central processing unit chip that can be clocked down to zero hertz.It can be stopped simply by stopping the system clock oscillator that is driving it, and it will hold its state indefinitely and resume processing at the point it was stopped when the clock signal is restarted, as...
, which means that it can be stopped simply by stopping the system clock oscillator that is driving it, and it will hold its state indefinitely and resume processing at the point it was stopped when the clock signal is restarted, as long as it is kept powered. CMOS circuits use extremely little power when they are not changing state, so an 80c88 that is on but not being clocked uses very little power.
The screen was not very tall, so text characters and graphics were compressed vertically, appearing about half their normal height. The display was capable of resolutions of 80x25 (text), 640x200, and 320x200. Pressing a lever between the two floppy drives just below the display detached the entire screen from the unit. This feature allowed the convenient use of a full-size desktop monitor while at one's desk, an early forerunner of the "docking station" concept.
The machine sold very poorly for a number of reasons. The Convertible was heavy, not much faster than the Portable it replaced (despite the newer CMOS
CMOS
Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...
processor and use of static RAM), didn't come with traditional PC expansion ports (such as serial port
Serial port
In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
s and a parallel port
Parallel port
A parallel port is a type of interface found on computers for connecting various peripherals. In computing, a parallel port is a parallel communication physical interface. It is also known as a printer port or Centronics port...
) without an add-on, and had a hard-to-read, oddly-shaped LCD
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
screen (the first screens lacked a backlight
Backlight
A backlight is a form of illumination used in liquid crystal displays . As LCDs do not produce light themselves , they need illumination to produce a visible image...
). It also competed against faster portables based on the Intel 80286
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...
that offered optional hard drives, from companies such as Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
, and laptops from companies such as Toshiba
Toshiba
is a multinational electronics and electrical equipment corporation headquartered in Tokyo, Japan. It is a diversified manufacturer and marketer of electrical products, spanning information & communications equipment and systems, Internet-based solutions and services, electronic components and...
and Zenith that were lighter and offered similar specifications, sometimes at half the price. With the screen, the keyboard was also widely criticized.
It was replaced in 1991 by the IBM PS/2 L40 SX, and in Japan by the IBM Personal System/55note, which was the predecessor to the ThinkPad
ThinkPad
ThinkPad is line of laptop computers originally sold by IBM but now produced by Lenovo. They are known for their boxy black design, which was modeled after a traditional Japanese lunchbox...
.
See also
- IBM Portable Personal Computer
- IBM PS/2 L40 SXIBM Personal System/2The 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...
- IBM PS/55 note
- History of laptopsHistory of laptopsBefore laptop/notebook computers were technically feasible, similar ideas had been proposed, most notably Alan Kay's Dynabook concept, developed at Xerox PARC in the early 1970s. What was probably the first portable computer was the Xerox NoteTaker, again developed at Xerox PARC, in 1976...
External links
- IBM-5140 Convertible and collection of old digital and analog computers at oldcomputermuseum.com