World Library  
Flag as Inappropriate
Email this Article

IBM PC Convertible

Article Id: WHEBN0000274034
Reproduction Date:

Title: IBM PC Convertible  
Author: World Heritage Encyclopedia
Language: English
Subject: IBM Personal Computer, Toshiba T1000, Floppy disk, IBM PC DOS, Timeline of portable computers
Collection: Ibm Laptops, Portable Computers
Publisher: World Heritage Encyclopedia

IBM PC Convertible

IBM PC Convertible
IBM PC Convertible
Release date April 3, 1986 (1986-04-03)
Introductory price 2000 US$ (today $4302.98)
Operating system IBM PC DOS with custom icon-oriented shell interface
CPU Intel 80c88 CPU @ 4.77 MHz
Memory 256 kB of RAM (expandable to 640 kB)
Storage Dual 720 kB 3.5" floppy drives
Display Monochrome CGA-compatible LCD screen.
Graphics 80x25 (text), 640x200, and 320x200
Power Battery: 9.6v/2400mAh (NiCd)
Power supply: 15 VDC, 2.7A.
Weight 13 pounds (5.8 kg)
Successor IBM PS/2 L40 SX
IBM PS/55 note

The IBM PC Convertible is the first laptop computer released by IBM. Released on April 3, 1986, the Convertible was also the first IBM computer to use 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. 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.


The PC Convertible used the CMOS version of the Intel 8088 CPU 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. The concept and the design of the body was made by the German industrial designer Richard Sapper.

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 will hold its state indefinitely by stopping the system clock oscillator. It can resume processing when the clock signal is restarted, as long as it is kept powered. The CMOS 80C88 processor uses very little power while the clock signal is stopped.

The screen was not very tall, so text characters and graphics were compressed vertically, appearing about half their normal height. The display could display twenty five rows of 80 column text and graphics modes of 640x200 and 320x200 pixels. 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 ports 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 [[

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.