Simple Computing

Vintage Computer

2011-01-31T14:47:00.000-08:00

This weekend I picked up a 1985 vintage Tandy Model 200 computer from WierdStuff Warehouse in Sunnyvale. This baby features a 80C85 microprocessor running 2.4Mhz (that's megahertz... with an "m"), 48K of static RAM, and a 40x16 LCD display.

This thing is simple computing. Built-in "applications" include a text editor for creating documents and an early spreadsheet that is surprisingly functional, if not a little odd. There's a 300 baud modem for dialing information services that no longer exist. Also, a terminal program that uses the RS-232 port to communicate with other computers, the only trouble is that fewer and fewer modern computers even support this old standard.

If you want to code up your own apps, go right ahead, there is a MS Basic built in. In fact much of the system administration is done through the basic interpreter.

The computer will run for 20 hours on a set of 4 "AA" batteries, try that with your 15" HD screen, Quad Core, 16GB RAM, Windows laptop!

Amazingly, this thing cost $1000 when it came to market in 1984. I paid $4.50 for it in 2011.

It's said that Bill Gates of Microsoft is nostalgic for this platform - Tandy model 100, 102, and 200, because it's the last product in which he personally wrote the majority of the code.

If you want to try one of these out with out actually getting one, then check out the VirtualT emulator available on SourceForge. But, be warned, using this thing is nothing like using a modern PC. It's takes a little getting used to how simple this computer really is.

Three Ways To Keep Computing Simple

2010-08-02T10:13:00.000-07:00

Run Linux - Linux is the only modern operating system that lets you operate your computer simply. DOS is pretty much a dead end, although it's okay for running on period hardware and to support some ancient programs. Linux affords you the opportunity to really get into computing rather than being just another technology consumer. Linux offers many ways to get involved in your personal computing. From desktop OSs to embedded systems, you have the power to get under the hood.
Use Command Line Tools - Does everything have to have a graphical UI? Is it possible to be productive in a non-graphical environment. Get down with the command line and see how much you can do. A world of productivity awaits when you get your hands off the dad-blamed mouse and don't have put your work on hold while closing the too-many windows you have open. I remember pining for graphics capability when all that was available was simple command driven systems, now we have more graphics than we can handle. Eat lobster every night and it starts to taste like soap.
Program Your Computer - We cast our information problems in terms of applications others have written to solve other problems. For the sake of expediency we modify the vision of our data into inputs for existing applications, like forcing a square peg into a round hole. Spend your energy programming your computer to solve your problems, create a round hole for your round pegs. Data processing needs haven't changed that much over time. We still need to add, subtract, multiply, and divide. We still need to process text in so many forms - email is the number one form of communication on the internet. And look at what people spend their time doing now - tweeting 140 chars at a time and "texting" like crazy. How about we view our computers as tools rather than just endpoints for communication that inundates us with noise?

The Python Programming Language

2009-01-21T21:38:00.000-08:00

I am finally getting around to saying a word or two about Python (www.python.org). Python deserves mention on a simple computing blog because while the language is not simplistic or limited, the syntax lends itself to expressing your computing ideas in a very natural way. Contrast this with a scripting language like Perl with its myriad special characters and non-intuitive expression.

Python is . . .

Object-oriented - Python is fully object oriented complete with classes, operator overloading, and multiple inheritance. Despite this, even a beginner can write useful code in minutes without getting anywhere near object-oriented programming.
Portable - Python compiles into portable bytecode which runs on any platform with python installed. The language itself is written in C and compiles on just about any platform including Linux, Mac, Windows, whatever...
Easy and fun to use - writing Python is a pleasure! You just sit down and write and out comes useful code.

How can you use Python?

Applications - complete toolkits exist for developing GUI applications that run on multiple platforms. These include wxPython and TKinter.
Prototyping - because you can write useful code in minutes, Python is great for proving concepts at the outset then porting the code to a compiled language for production.
Internet scripting - built in internet modules let you easily retrieve and parse HTML (web scraping), move files with FTP and communicate with email using SMTP and POP protocols. Python is the language behind entire web publishing frameworks, such as Django. Or, you can write simple CGI scripts that add interactivity to your web site.

Really the question is what can't you use Python for?

P.S. - Python includes a built-in module for another simple computing winner, SQLite!

Building A Computer?

2009-01-10T09:27:00.000-08:00

Building a computer these days conjures images stuffing of CPUs, memory modules, and hard drives into a motherboard and throwing the whole thing into a big black case and running Windows or Linux.

But how about really building a computer, with micro chips and a soldering iron?

In a recent SolderSmoke podcast OM N2CQR asked the audience if anybody had a spare CD4019 chip to replace a defective one in his frequency counter, so I searched through my junque box for the part, but alas no such luck. However, in the process I cataloged the ICs (so I can just look up parts in the future) and found quite a trove of IC chips including logic, memory, and several CPUs. A microcomputer or other microprocessor based device could be built with the parts on hand, I thought.

I remember fondly my days in high school when we had a H-89 to play and learn with and then later, learning about assembly language programming using 8080A "trainers" and decided it would be fun to recapture some of that magic. So here's what I have to work with:

Several CPUs including Z80, 8080, and V20 chips.
Z8 romless microcontroller
6kb worth of 2114 static RAM
A 2764 EPROM
assorted 74-series and CMOS chips
several DAC08 D/A converters

The project guidelines are simple, whatever is built must:

use mainly parts on-hand. A few inexpensive parts may be purchased if needed, but no big cash outlay is allowed.
be useful. The unit must be capable of performing some useful work.
look good. It should be housed in an attractive enclosure with neatly labeled controls.

Some possible projects include:

A microcomputer, this is the obvious choice. Some very nice work has been done with homebuilt computers. The Magic-1 is a handmade microcomputer including homebrew CPU, not a microprocessor. Nice!
A music synthesizer. The DAC08 chips could be used for waveform synthesis. The Z80 in particular, has been used in several synthesizers for control and sound generation.
A weather data monitor and logger. A microprocessor based unit could sample wind speed, direction, air temperature and barometric pressure.

My inclination is toward using the Z80 as they are more sophisticated than the 8080A and I have two of them on hand. With only 6K of static RAM, the memory situation is a bit lean, but maybe I can pull the old DRAM chips from my PC XT. That's 640K, and Bill Gates said that should be all I need, or did he?

Run legacy DOS applications in Linux

2008-10-22T09:19:00.000-07:00

I use Linux as my personal computing OS and it does pretty much everything I need, is stable, relatively secure, and free. However there are times when I could really use a DOS box to run some ancient DOS based program that doesn't have a Linux equivalent. This isn't a problem for Windows users who can just open a command prompt window. And it's not a problem for Linux users either, with dosemu an open source DOS emulator/virtual machine.

For Ubuntu/Debian dosemu is intalled simply with:

apt-get install dosemu

A specific directory becomes your "C:" and you can run all those old DOS programs. I have to say that seeing autoexec.bat and config.sys in my C:\ made me a little nostalgic for the old days. The feeling passed quickly though.

Global text replacement

2008-10-17T16:13:00.000-07:00

One of the things I really like about Linux is the powerful file manipulation abilities it offers. Recently I needed to replace one phrase in a whole bunch of files with another. I copied the files from my Windows PC to a Linux machine and used the following shell commands to perform the replacement:

#!/bin/sh
for file in *; do
mv $file $file.old
sed 's/FINDSTRING/REPLACESTRING/g' $file.old > $file
rm -f $file.old
done

I didn't come up with the shell commands myself, but rather found them after a google search, so I can't claim credit for it. However, maybe you will find the script useful to replace text in your own files.

Small. Fast. Reliable. Choose any three.

2008-07-26T08:32:00.000-07:00

I've been really hung up on this program since I "discovered" it about a year ago. It's a honest to goodness SQL database engine implemented in less than 200 kilobytes. I am talking about SQLite.

The software is in the public domain, which is interesting all by itself, and it's been integrated into tons of commercial programs and devices. SQLite features include:

No configuration or administration needed
Serverless
Supports transactions
Cross platform
Fast!
Public domain

I use SQLite to track weather data that I collect at my home. I've also used the software as the heart of a simple, yet fairly smart, amateur radio logging program built with SQLite and a bash script.

SQLite fits nicely into the simple computing philosophy. It works well from the command line and without a lot of "moving parts" it's extremely reliable. The database files are portable across different OS's and filesystems and the entire database is in a single file which makes copying or backing up a database as easy as copying one file. In fact I carry several databases around on a small USB stick. For those that absolutely need a gui, there is a light weight front end available as a Firefox extension, however I prefer to use it from a command line.

# tea -earl grey -hot

2008-07-25T22:32:00.000-07:00

This blog is about simple computing. Simple computing is a philosophy that says computers can be our servants, save us time, and make our lives better when we use them in simple ways. Computers are a collection of tools and simple computing is about using the right tool for the job. Here are some of the tasks where simple computing excels:

Data Processing
Data Storage
Communication

Do you remember when the simple tasks were all that our computers were capable of performing? Now we have so much cheap processing power that we don't know what to do with it all, so we pile on complexity to keep our CPU's busy. But has complexity made our lives better? I don't think so. There are specific ways in which the complexity of modern computing systems have opened new worlds to us and I am pleased to be able to take part in them. But on the other hand, many of our needs have not changed significantly in the last 20 years. Complex solutions to simple problems breed even more problems, yet we've been snookered into believing that complexity equals sophistication.

One of the biggest blunders of modern computing era is total domination of the graphical user interface. GUI's are so dominant that a huge percentage of computer users have never even heard of the command line interface, let alone witnessed its simple power. The desktop is a disaster in terms of accessing information, controlling hardware and software, and getting things done. I don't remember seeing officers on the U.S.S Enterprise (NCC-1701D) shuffling through windows and icons to transfer power to the forward shields, or even to make a hot beverage. And icons! What a collection of worthless little smudges!

Welcome to simple computing.