I came across these wonderful machines in 2004, just
as I was about to take a break off work and embark on a computer engineering
degree. Looking at the internals of these machines, the realisation of the
ingenuity and greatness of our predecessors got me hooked.
|
|
Friden
EC-130
- Around 325 transistors
and 650 diodes
- Magnetostrictive delay-line
memory
- Highly efficient and
elegant architecture
- $2195 in 1963
|
First, I discovered the Friden EC-130, the
first fully transistorised four function calculator, where I spent days uncovering
information on online museums, reading accounts by former employees and digging
for data in ancient patents. As if that wasn’t enough, I then discovered HP’s Model 9100A, an
equally revolutionary, fully transistorised, scientific calculator.
In 2007, I got my chance. With a perfectly valid
excuse to learn VHDL and a bit of faith from my academic supervisor, I had four
weeks to design a machine in the spirit of the original.
|
|
21st
century reincarnation
- Designed using VHDL
- Powered by Xilinx
Spartan-3
- Deceptively simple DIY analogue
interfacing
- Oscilloscope with XYZ
inputs required
|
What’s provided here isn’t a clone of the Friden
EC-130, but it’s close enough in spirit. The original’s design elegance exuded
from the overall architecture down to the finely tuned values of resistors and
speed-up capacitors. The man behind it, Robert Ragen, was a brilliant engineer
and his designs from four decades ago still inspire.
Special mentions
- Rick Bensene, maintainer of the Old
Calculator Museum, for nurturing the spark and for his assistance in
digging out those ancient patents.
- Fiona at Digilent
Inc, from where I got my Xilinx
Spartan-3 development kit, who was kind enough to send a 400k gate kit
for the price of the 200k version.
- Clive Maxfield, editor of pldesignline.com, for promoting
this project on his blog.
|
