Electronic Mill Game

I created an electronic Mill Game board in 1977 .. The mill game is also referred to as nine-man morris, mill, mills, the mill game, merels, merrills, merelles, marelles, morelles, ninepenny marl and “cowboy checkers” (it was often printed on the back of checkerboards). The Mill game is believed to have been played in the Roman Empire.



  • https://playpager.com/mill-game/

Data Recorder ZE 601

The Data Recorder was developed in 1977 at the Institute of Electronics of the ETHZ by Dr. Rolf Zinniker in relation with the MC6800 Microcomputer system. The electronic interface card with an FSK ( frequency shift keying) modem was embedded in a cassette tape recorder from Sanyo, Model M2502U.



The following documents can be downloaded:

Microcomputer system MC6800

The development of the the microcomputer system MC6800 started in late 1975 at the Institute of Electronics of the ETHZ by Dr. Rolf Zinniker, Dr. Kurt Mühlemann and myself. The system was based on the  8-bit microprocessor 6800 designed and first manufactured by Motorola in 1974.

The operation of the system was done with an external keyboard and an external oscilloscope display. Both units are connected with a parallel interface.

The system consist of the following elements:

  • a power unit with +5 Volt 6 Ampere, +15 Volt 1.6 Ampere and -15 Volt 1.6 Ampere
  • a microprocessor unit (MPU) with ROM (read-only memory); max 1 KByte
  • a memory board with RAM (random access memory); max 8 KByte
  • a peripheral interface adapter (PIA) to connect a keyboard
  • an asynchronous serial interface (ACIA) to connect a data recorder (tape recorder or floppy disk) or a printer
  • a parallel interface to connect the oscilloscope display

Several units have been build and were used in the electronic workshops for students. When I leaved the Institute of Electronics in march 1978, I received the prototype of the MC6800 system as a compensation for the numerous extra working hours which I spent in the microcomputer laboratory.

The following figures show the different units of the MC6800 system:

Power Unit

Memory 8KB RAM



Display Interface

Light Pen



Marco Barnig with the MC6800 MicroComputer in 1976 in Zurich

A german user guide can be downloaded as a pdf file.


The +12V output of the Power Unit is faulty. The light pen has not been tested. The other units should work as expected.


Chumby is an embedded computer which provides Internet and LAN access via a Wi-Fi connection. Through this connection, the Chumby runs various software widgets. This consumer electronics gadget premiered on August 25, 2006 at Foo Camp and was released to around 100 alpha release testers at this event. Foo Camp is an annual hacker event hosted by publisher O’Reilly Media.

The original Chumby resembles roughly to a small clock radio and features a small resistive touch-screen housed in a leather and plastic exterior with six color options. I own the basic black leather model CHY-A01-A. Different models were released and offshoot versions were introduced by other suppliers, for example the Sony Dash. Chumby devices run a modified Linux kernel. Hacking the Chumby hardware and software was encouraged by the manufacturer. The lead hardware engineer at the former Chumby Industries, Inc. was the hacker Andrew “bunnie” Huang.

figure Chumby apps

The Chumby was part of a whole ecosystem with bags to carry them, chumby charms (small plastic collection sets) designed by famed designer Susan Kare and hundreds of apps to install on the device. Susan Kare created many of the interface elements for the Apple Macintosh in the 1980s. She was also the Creative Director of NeXT, the company formed by Steve Jobs after leaving Apple in 1985.

Chumby bag
Chumb bags
Cumby powerplug
Chumby charms

The Chumby apps were sort of precursors to the mobile apps introduced in 2008 by Apple (App Store) and Google (Google Play).

In 2012, Chumby went into bankruptcy and was liquidated. The server needed to keep the devices running went offline in 2013. The assets were purchased by Duane Maxwell, the former Chief Technology Officer of Chumby Industries, who formed Blue Octy, LLC to revive the chumby technology. Without a server, all devices only display a single widget, referred to as the Space Clock.

spaceclock figure 0
spaceclock figure 2
spaceclock figure 3
spaceclock figure 4
spaceclock figure 1

The revived Chumby service requires a $3 monthly subscription fee to get access to over 1000 apps. An open source firmware is available at SourceForge for free that allows existing devices some of the functionality of the paid service at no cost. Help is provided by the ChumbySphere forum. Resuming the manufacturing of new Chumby devices is not planned, but some spare Chumbys from the unsold inventory are still available at the Chumby Store.

The following figures show the display sequence when the Chumby is started:

chumby start 1
chumby start 2
chumby start 3
chumby start 4
chumby start 5
chumby start 6
chumby start 7
chumby start 8
chumby start 9
chumby start 10
chumby start 11

The last screen is only displayed in case of problems, usually the space clock is shown if there is no valid subscription.