Introduced on April 3, 1986, the IBM PC Convertible was IBM’s first laptop computer and was also the first IBM computer to utilize the increasingly common 3.5 inch floppy disk drive. Like modern laptops, it featured power management and the ability to run from batteries.

Weighing in at 13 pounds (5,8 kg), the PC Convertible was based on the Intel 80c88 CPU (a CMOS version of the Intel 8088) running at 4.77 MHz, 256K of RAM (expandable to 512K and later 640K) and featured dual 720K 3.5″ floppy drives, a monochrome CGA-compatible LCD screen and a proprietary snap-on expansion system.

The PC Convertible was priced at $2,000 for a standard configuration. An internal modem could be added for an additional $450. Snap-on expansion adapters could be added , such as a serial/parallel adapter for $195 and CRT display adapter (640 X 200) for $350.

All of these adapters “convert” the Convertible into a more useful machine, but with all of them installed, the system grows an extra 7 inches in length and the weight increases from 12 pounds to 20 pounds, making it rather long and unwieldy.

Introduced into a marketplace that included faster Intel 80286 CPU-based portable computers, many that sold for approximately half the PC Convertible’s $2,000 price tag and others that featured hard drives, the computer sold very poorly. In reviews the PC Convertible’s screen, keyboard and proprietary expansion system were also widely criticized.

Still, with its power management, battery power pack and folding design, the PC Convertible helping establish many of the important features for portable computing that exist today.

Specifications

• Introduced in April 1986
• $2000 with 256K RAM
• RAM expandable to 512K originally, and later 640k
• Intel 80C88 CPU (CMOS version of Intel’s 8088)
• Monochrome LCD display, CGA resolution, able to add external monitor
• IBM PC-DOS with custom icon-oriented shell interface
• Dual 720K 3.5″ floppy drives
• Proprietary snap-on extension in rear for various expansion modules and snap-on peripherals

References

• oldcomputers.net/ibm5140.html
• en.wikipedia.org/wiki/IBM_Convertible
• www.seasip.info/VintagePC/5140.html