Miscellaneous
Pianola
The technikum29 is quite versatile – beside all the communication and computer technology we also show very special exhibits: This is a fully executable pianola, year of manufacture about 1910-1915.
It's a great experience see and hear such old jukeboxes, typically made
only of natural materials like leather, gum, wood, bone glue, felt, metal, paper,
ivory and glas.
By assembling these elements on an intelligent way, one could
build a simple mechanical machine which is especially impressive
for today's people. Here at the technikum29, we will show you how
this device works, we will explain the basic functionality and
play challenging compositions. While having covers removed, you can
even see the fascinating mechanics working.
Movie projector "Dresden 1"
The technikum29 has a movie projector from 1951 (there are more and even older projectors from the 1930s that are stored in the archive for lack of space).
Movie projectors have always been very complex devices. At that time,
the bright picture projection was archived with an arc light which was
generated between two carbon pencils. The waste heat was deflected via a
chimney pipe!
Since the pencils got shorter and shorter while the movie went on, they
had to be moved continously closer together for producing a constant
luminosity. Otherwise the light goes out.
We will repair this device to show an original newsreel from the 1960s.
Siemens Demonstration Computer
Siemens educational computer
This demonstration model was build in 1973, when personal computers were not
invented for a long time yet. Engineers had to be trained to understand
computer architectures. Therefore, this big education model was constructed.
It is a giant implementation of a typical register machine where 126 lamps
display all registers, control, ALU and RAM, including the data flow.
Featuring a mutable clock pulse and only 4 bit word with, elementary opcodes
could be reproduced in a very illustrative way. The device can be toggled to
process one instruction or one cycle a time.
On the left side, the computer program could be directly "written" by plugging
cartidges labeled with assembly instruction mnemonics or numerical values
(immediate operands). On this cartiges the user could directly read the binary
value of the machine instruction which will be the content of the corresponding
random access field. As you might guess, the computer cannot change the program
memory without user interaction, so this model actually implements an Harvard
architecture, even though the (german) labels on the frontend suggest something
different.
The picture above shows a currently running program that adds memory cells. It
shows that computer word lengths do not limit the length of proccessable
numbers.
It is a wonderful device that can even be used today to understand the elementary
workflow of modern high end desktop CPUs.