After Hours

The Osborne 1 and the TRS-80 Model 4P exposed

Sure there has been lots of discussion of the Apple MacBook Air and its so-called innovations, but the real computer innovation occurred almost 30 years ago with the Osborne 1 personal computer.

When it hit the market in 1981, the Osborne 1 started a revolution that the MacBook Air merely continues today. The Osborne 1 was the first truly portable completely self-contained personal computer. Check out the TechRepublic Dinosaur Sighting Photo Gallery to see what passed for a portable PC all those years ago.

Unfortunately for the Osborne Computer Corporation, founder Adam Osborne had more enthusiasm for his company's creations than market savvy on how to promote them. After a few months of initial success, Mr. Osborne began to talk in glowing terms about the next generation of Osborne computer, which was called the Executive. It would have a bigger screen and other improvements. His description sounded so wonderful that some potential customers decided to stop buying the Osborne 1 and to wait for the pending Executive.

Coupling this market slow-down with a vigorous increase in competition doomed the company to a spiral of losses and eventually bankruptcy. But the void was quickly filled by the likes of Radio Shack and its TRS-80 line of products. In the aforementioned TechRepublic Dinosaur Sighting Photo Gallery you can get a good look at the TRS-80 Model 4P.

The Model 4P was very similar to the Osborne 1, but benefited from two years of innovations and revisions. The Model 4P had a larger screen and a built in modem, which made it an even more capable luggable computer.

In the next few weeks, I will be putting these two pioneering computers under the microscope in a TechRepublic Cracking Open Photo Gallery. We'll see what makes them tick and wax nostalgic about how things used to be in the world of portable computing.


Mark Kaelin is a CBS Interactive Senior Editor for TechRepublic. He is the host for the Microsoft Windows and Office blog, the Google in the Enterprise blog, the Five Apps blog and the Big Data Analytics blog.


I still have mine. Got it in 1982.


If I remember correctly, rather than the Osbourne failing to be bought because of the talked up Osbourne 2 (Executive) it was displaced by the Kaypro that while it only had 1 floppy, it had a 9 inch screen. I remember working on my Osbourne with its tiny five inch screen very well. I either leaned very close to the monitor or I squinted. Finally, I took apart an overhead projector and removed the magnifying lens and mounted it in front of the CRT. Osbourne also did something else from the programming arena that was different. ASCII only uses seven bits and a byte uses eight bits. Most computers of the time wasted the eighth bit. Osbourne used the eighth bit to flip the flashing of the character. While the Osbourne was considered to be a plain vanilla machine, it was advanced for its time. It used the 8 mhz Z80 CPU rather than the 4 - 6 mhz 8080 CPU of most of the other computers of the time. There were a limited choice of programming languages available. I had Assembly, C, Fortran, and Pascal. If you wanted to get any real work done, you used assembly. I had a difficult time translating from 8080/Z80 assembly to 80x86 assembly when I finally went to the IBM compatibles with the 80286.

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