The TRS-80 Model 100 is a computer you owe a lot to, even if you don’t recognize it. Released in 1983 by Tandy (now known as RadioShack) for $1099 USD, the Model 100 was one of the world’s first “notebook” computers. At the time its design was radical, as computers had always been large objects tethered to bulky CRT monitors; the Model 100 helped introduce concepts we all take for granted now, such as all-in-one construction, integrated LCD display, and the ability to run on battery power. Selling over 6 million units, the Model 100 proved that a highly portable computer could be successful, and we’re still seeing the effects of that today.
But after nearly 30 years, the Model 100 is really showing its age. The hardware specifications are below what we would expect even from a microcontroller like the Arduino, to say nothing of a modern computer or smartphone. Does this old tank have any life left in it, or is it best suited for the museum? Could you connect it to a modern system and get new software for it, even if you wanted to?
|TRS-80 Model 100|
|Processor||Intel 80C85 @ 2.4 MHz|
|RAM||8KB, Upgradable to 32 KB|
|Storage||32 KB ROM, Optional 3.5 Inch Floppy Drive|
|Screen||8 line, 40 character LCD @ 240×64|
|Power||Four AA Batteries|
|Networking||Built-in 300 baud modem, serial port|
|Dimensions||300x215x50 mm, approx weight 1.4 kg (3.1 lb)|
With hardware specs like that, you might wonder why anyone would bother getting one of these things up and running again. Interestingly enough, some of the Model 100′s key features are still in demand for certain applications. The Model 100 is able to run an incredible 20 hours on a set of 4 AA batteries, and its low energy consumption make it well suited for conversion to solar or other off-grid energy sources. Combined with the fact the machine doesn’t have a single moving internal component and has a built in analog modem and serial port, the Model 100 is very well suited to data collection and reporting in remote locations or areas where more delicate hardware may have trouble coping.
For the “nuts and bolts” types out there, there is no better teardown and examination of the Model 100 than what David L. Jones has done for his EEVblog:
Its renowned reliability aside, there are a number of interesting bits of trivia involving the Model 100 which has helped cement its position in computing history. Such as the fact that the Model 100 is the last product for which Bill Gates personally wrote a sizable part of the code.
Part of my nostalgia about this machine is this was the last machine where I wrote a very high percentage of the code in the product. I did all the design and debugging along with Jey.
In a twisted bit of irony, the Model 100 also has the distinction of being one of the only devices that was actually affected by the “Y2K Bug“; the theorized glitch which would cause computers to become confused as the year switched over from 1999 to 2000 due to the fact that many old pieces of software were only designed to take into account the last two digits of the year, and assumed the first two were always going to be “19″. As predicted, the Model 100 believes this to be the year 1912. Thanks, Bill.
Whether you had one from the 80′s or bought one on eBay recently, you’re going to want to get some software for it. Luckily there is a very dedicated TRS-80 community out there that is still pumping out software for the various TRS-80 models. For the most up to date information and software, check out the indispensible Club100:
There you can find software for your Model 100, documentation on the computer and its accessories, information on how to connect the Model 100 to other devices, and basically anything else you could possibly want to know about a 30 year old computer.
You may also want to check out the WEB 8201 site, which is dedicated to the NEC PC-8201A, but also serves up software downloads for its close relatives including the Model 100.
Before you dig into the hardware side of things, you may also want to take a look at Virtual T, an open source Model 100 emulator for Linux, Windows, and Mac OS. Using Virtual T, you can test out (or write) software before putting it on the actual Model 100 hardware. This gives you the opportunity to test drive a piece of software without taking the time to install it on the real device.
No matter how you ended up with a Model 100 and the desire to do something with it in 2012, one thing is certain, you won’t be doing a whole lot with it until you can install some new software. There are actually a lot of different ways you can go about this, using different protocols, commands, and hardware. The methods used even differ depending on what you want to transfer, as you can transfer plain text files faster (and in different ways) than you can BASIC programs.
For the sake of this guide we are going to assume that you are only interested in transferring BASIC programs from your Linux computer to your Model 100. We’re going to use the method which requires the fewest steps and seems to work the most reliably, though unfortunately, this is also the slowest method. Of course, you probably shouldn’t expect much in the way of speed on a 2.5 MHz computer in the first place.