Leading Edge Model D

PC marketed by Leading Edge Hardware

The Leading Edge Model D is an IBM clone first released by Leading Edge Hardware in July 1985. It was initially priced at $1,495 and configured with dual 5.25" floppy drives, 256 KB of RAM, and a monochrome monitor. It was manufactured by South Korean conglomerate Daewoo and distributed by Canton, Massachusetts based Leading Edge. Engineer Stephen Kahng spent about four months designing the Model D at a cost of $200,000. Kahng later became CEO of Macintosh clone maker Power Computing. In August 1986, Leading Edge cut the price of the base model by $200, to $1,295, and increased the base memory of the machine to 512 KB. The Model D was an immediate success, selling 100,000 units in its first year of production. It sold well for several years, until a dispute with dealers forced Leading Edge into bankruptcy in 1989.

The Model D initially featured an Intel 8088 microprocessor at 4.77 MHz, although later models had a switch in the back to run at 4.77 MHz (normal) or 7.16 MHz (high). Earlier models have no turbo switch and run only at 4.77 MHz, while a few of the later ones (seemingly very rare) are 7.16 MHz only. Four models are known: DC 2010, DC 2011, DC 2010E, and DC 2011E. The "E" seems to correlate with the capability of running at 7.16 MHz. The addition of the Intel 8087 floating point unit (FPU) coprocessor is supported in all Leading Edge Model D revisions with an onboard 40 pin DIP socket. Unlike the IBM PC and IBM PC/XT, the Model D integrates video, the disk controller, a battery backed clock (real time clock or RTC), serial, and parallel ports directly onto the motherboard rather than putting them on plug in cards. This allows the Model D to be half the size of the IBM PC, Motherboard revisions 7, 8, WC1 and WC2 come with 768 KB of RAM installed (640 KB available to the user). Some models have a monochrome/CGA selection switch, with a single port used for both modes. Some models have both a Monochrome and a CGA port, also with a switch to change modes (and ports). Leading Edge dealers had difficulty keeping the 20 MB model in stock. The Model D was the first Korean made PC to be sold in the United States, and at the time of its introduction, it undercut the price of similar IBM PC compatibles by $500. The $1,495 list price was the lowest of seven compatibles with comparable configurations in a September 1985 InfoWorld chart, and under half the price of the $2,820 IBM PC. Along with the Tandy 1000 and Epson Equity series, the Model D was one of the first IBM PC compatible computers to become popular for home use, due to its low price and good reviews. Many home oriented software packages for the PC specifically cited the Model D along with the Tandy and Epson models as compatible hardware. Leading Edge was Phoenix Technologies' first customer for its IBM compatible BIOS, and the Model D was one of the first PCs on the market to use the Phoenix BIOS. Although advertised as 100% IBM compatible, letters published in the January 13, 1986 issue of InfoWorld identified compatibility issues with several popular software packages and aftermarket hard drives. Syndicated newspaper columnists T. R. Reid and Michael Schrage, writing in April 1986, predicted that the popularity of the Model D would lead to hardware and software vendors specifically testing for compatibility. In spite of these early reports, the Model D sold well. In early 1987, Daewoo was producing 13,000 units per month and failing to keep up with demand. As a result, buyers waited 2–8 weeks before taking delivery.

PC Magazine in October 1985 called the Model D "the clear winner" among six inexpensive PC compatibles it tested. The review noted the computer's many included hardware features, and concluded that it "may represent the next generation of personal computing: about as compact as full IBM hardware compatibility allows, full featured, quite well made, and alluringly priced". The Model D received 4 out of 5 stars from InfoWorld in December 1985. The magazine praised the computer's value and ease of setup ("the whole operation takes less than 20 minutes, even if you know nothing about computers and take your time"). It noted that the magazine had previously given the bundled Leading Edge Word Processor a very good review, and reported that the Model D was even compatible with IBM diagnostic software, unlike the Compaq Portable and others. InfoWorld concluded "We recommend it highly, especially to the budget conscious beginner". A positive October 1986 review in Popular Mechanics cited its low price and the quality of its keyboard. It received good reviews in other computer magazines and Consumer Reports magazine.