The Gizmo History Report: The TRS-80 Model 100

I was in the Air Force in 1983, serving at Hahn AB in Germany (now a civilian facility somewhat misleadingly renamed Frankfurt Hahn Airport, although it's 110 km-- 68 miles-- away from Frankfurt).

In March, I was given a temporary duty assignment back to the US, and I was able to take some leave to go back home to Miami.

I dropped in at the old Radio Shack Computer Center, where I used to hang around-- yeah, I was the kind of kid who would hang around at a Radio Shack Computer Center-- and they had this new gizmo for sale. In fact, it had just gone on sale a few days earlier; I'd never even heard of it.

It was the TRS-80 Model 100, the first laptop computer to achieve mainstream success. I made up my mind to buy it on the spot, although it cost me $800 at a time when that was about three months of my disposable income.

(The Wikipedia entry on the Model 100 is here, and Dave Dunfield's great Model 100 page with interior photos, manuals, and original advertisements is here.)

Wikipedia says Radio Shack sold more than six million units of the Model 100, which was made by Kyocera in Japan. Kyocera sold its own version, and both NEC and Olivetti had private-label models. Over time, Radio Shack added the Model 102 and the Model 200 to the product line.

In an interview with the Smithsonian Institution, Microsoft's Bill Gates said the Model 100 "was the last machine where [he] wrote a very high percentage of the code in the product." Gates and co-developer Jey Suzuki produced a 32KB ROM containing a BASIC interpreter, text editor, a telecommunications program, and basic address-book and scheduling functionality.

The code executed in place on this ROM, and user data was stored in ultra low-power CMOS RAMs, so there was never any bootup delay. The machine used four AA alkaline batteries, which would give days of ordinary use and literally years of standby power for the RAM. I stopped using my Model 100 in 1990, and I've replaced the batteries four or five times since them; all the data files I used to use are still there. The machine thinks it's 1999, though; apparently Gates never thought one might still be working 17 years later.

The Model 100 had an excellent keyboard and a highly legible LCD showing eight lines of 40-column text or a monochrome bitmap mode with a resolution of 240 x 64 pixels. These features, combined with the long battery life and a reputation for rock-solid reliability, made the Model 100 a very serviceable portable word processor. Many of these machines went to students and reporters; in fact, newspapers continued to rely on the Model 100 and Model 102 for years after Radio Shack discontinued them, supporting a strong market for used models.

I found it to be a great machine for simple software development, too. I wrote a few hundred programs in both BASIC and machine language on my Model 100, including a disassembler, a better telecomm program, and a sample implementation of the RSA cryptosystem, although the machine was too slow for this code to be really useful. I also used it to call computer bulleting board systems all over the country through Telenet Inc.'s PC Pursuit service.

I've always been a little surprised that nothing like the Model 100 has seen any real success since then. The Wikipedia article on the Model 100 describes a few of the attempts, but people generally haven't been willing to give up instant-on and ultra-long battery life to get full desktop-PC compatibility.

But that may be changing. I think the XO laptop from the One Laptop per Child association, the Eee PC from Asus, Intel's Classmate PC, and Palm's Foleo are the spiritual successors of the Model 100.

The XO and Classmate are aimed at institutional customers, but end-user sales are the real test. If users buy any of these machines with their own money, then we'll know that the Model 100's success wasn't just a fluke, that there really is a niche here. That will provide a motivation to the industry to hone in on the concept, and I'm really looking forward to seeing the result of this work.